Category: Treatments & Protocols

Whole-body infrared delivers infrared light and radiant heat to the entire body, not to one limb or one foot. At Regenerve it is supportive care. It sits inside a plan built around the specific driver of your neuropathy — metabolic, nutritional, autoimmune, toxic or structural. It is never a treatment given on its own.

Two things are true at once, and this page holds both. Medicare does not cover infrared therapy devices for peripheral sensory neuropathy, so you pay for a course out of pocket.² And the randomized evidence behind that determination studied a different delivery method. It used narrowly selected patients, for a few weeks at a time. Neither fact settles what infrared can do for one specific person. This page explains why.

Does Medicare cover infrared therapy for neuropathy?

Effective October 24, 2006, the Centers for Medicare & Medicaid Services made a ruling on infrared therapy devices and related accessories. It found them not reasonable and necessary under section 1862(a)(1)(A) of the Social Security Act. Infrared and near-infrared light and heat are not covered anywhere in the country for diabetic and non-diabetic peripheral sensory neuropathy. That includes monochromatic infrared energy. The same goes for wounds and ulcers of the skin and the tissue under it (subcutaneous tissues). It also goes for symptoms such as pain from those conditions. The policy is on record as national coverage determination 270.6. It was implemented January 16, 2007.²

Know this before you start anything, because it decides how the service is paid for. Patients sign an advance beneficiary notice for non-covered services. Then they pay out of pocket. Anyone who offers you infrared for neuropathy and implies it will be billed to Medicare is either mistaken or misleading you.

A coverage determination is not a clinical finding about your nerves. It is a program’s decision about what it will buy. It was made under a legal standard, at a fixed point in time, on the evidence available then. That is a real and important decision. But it answers a different question from whether a therapy helps a particular person with a particular driver. The rest of this page deals with that clinical question.

What is the difference between infrared pads and whole-body infrared?

The word covers a wide band, and the difference is not cosmetic. It decides which studies apply to what you are being offered.

Contact pad devices

These are rows of small infrared lights (diodes) set in flexible pads. The pads are strapped against the skin of the foot and lower leg. This is the device the 2006 coverage determination describes and regulates. It falls under the durable medical equipment benefit category.² With very few exceptions, it is also what the randomized neuropathy studies tested. In this field the technique is usually called monochromatic infrared energy.

Whole-body radiant infrared

This is a cabin or enclosure that raises body temperature with radiant infrared. There is no pad. There is no fixed wavelength aimed at a target tissue. The dose is very different, and so is the amount of tissue it reaches. In regulatory terms, infrared lamps emit across roughly 700 to 50,000 nanometers and are meant to provide topical heating (heating at the skin).³

When you compare what is on offer, ask which of these two you are actually buying. A study of pads at 890 nanometers on the sole of a foot does not automatically describe a warm cabin, in either direction.

What do the infrared therapy trials for neuropathy show?

A 2017 systematic review and meta-analysis in the Brazilian Journal of Physical Therapy pooled six randomized controlled trials. They covered 594 feet in 304 patients with diabetic sensorimotor polyneuropathy (nerve damage from diabetes).⁴ It is the best single place to see this body of work. Its own rules set the limits of what it can tell you.

The review included randomized trials of light-emitting diodes in the 750 to 1300 nanometer range. By rule, it left out any trial that applied the treatment to a region other than the feet. It also left out any trial with fewer than three days of treatment.⁴ Every device in it was a pad set placed on the foot and lower leg, at 870 to 890 nanometers. Each delivered 1.30 to 1.95 joules per square centimeter per minute. Follow-up ran from one and a half to twelve weeks, with a median of four weeks.⁴

The pooled result

Across four trials and 402 feet, infrared did not increase the number of plantar regions (spots on the sole) that could feel the 5.07 monofilament, compared with control. The standardized mean difference was 0.22, 95% confidence interval −0.07 to 0.51.⁴ A subgroup with follow-up of two weeks or less did show a gain: standardized mean difference 0.41, 95% confidence interval 0.18 to 0.64. That gain was gone beyond two weeks: standardized mean difference −0.12, 95% confidence interval −0.50 to 0.26. The difference between those subgroups was itself statistically significant at p = 0.02.⁴

For pain, the review set aside one non-blinded trial. After that, pain fell less in the infrared groups than in the sham groups: mean difference 0.40 points, 95% confidence interval 0.30 to 0.68.⁴ The review’s authors offer a specific reading of that, and it is worth knowing. In a nerve that is losing fibers, restoring some feeling can restore the ability to feel pain. So falling pain scores in this disease are not always good news.⁴ Using the GRADE system, the authors rated the overall certainty of evidence as low for both outcomes. That means further studies are likely to change the estimate.⁴

The largest and longest of the trials

A 2008 double-blind, sham-controlled trial in Diabetes Care randomized 69 people with diabetes. Of those, 60 patients and 120 limbs completed it. Units were used at home for 40 minutes a day for 90 days. The investigators measured nerve conduction velocities and vibration perception threshold. They used four grades of Semmes-Weinstein monofilament. They used the Michigan Neuropathy Screening Instrument. They also used a 10 cm visual analog pain scale and a quality of life tool built for neuropathy. There were no significant differences between active and sham on any of them.⁵

The entry rule that matters here is spelled out in the published report. Entry required a vibration perception threshold between 20 and 45 volts.⁵ That is a severity band. People with milder loss below that band were not enrolled. Neither were people with the most profound loss above it. We could not obtain the full eligibility list from the publisher. So we do not describe any exclusions beyond the one the report states.

The trial where both groups improved

A 2005 randomized, double-blind, placebo-controlled study in Diabetes Care followed 39 people. All had diabetic peripheral neuropathy. They got 30 minutes of active or placebo infrared three times a week for four weeks. Then they had four weeks with no treatment. The number of sites that could feel the 5.07 monofilament rose significantly in both the active and the placebo groups. There were no significant differences between the groups at any measurement point.⁶

The Medicare review of this trial recorded the size of that placebo movement. Over the blinded phase it was about +0.37 sites in the active arm and +0.57 sites in the sham arm, roughly 39% and 40% above baseline.³ This is the single most useful thing in the whole literature. It is why a clinic showing you before-and-after numbers with no control group has shown you nothing. And it applies to glowing reports about any modality, not only this one.

The trial that separated symptoms from structure

A 2021 randomized sham-controlled study in Neurology India enrolled 38 people with type 2 diabetes and painful diabetic peripheral neuropathy. Of those, 30 completed it. Treatment was three times a week for 12 weeks. Intraepidermal nerve fiber density (the count of tiny nerve endings in the skin) was measured on a 3 mm skin punch biopsy at baseline and at 12 weeks. Mean age was 59.1 years. Mean diabetes duration was 12.9 years, and mean symptom duration was 3.9 months.⁷

Nerve fiber density did not increase with treatment. Pain did move. The median visual analog scale score fell 5.1 points with infrared against 3.0 points with sham, intergroup p = 0.01. Quality of life on the Norfolk instrument also differed, at p = 0.021. The authors concluded that infrared does not increase nerve fiber density over short-term use. But they found it does provide symptom benefit and improved quality of life.⁷

For a patient deciding what to expect, this is the most informative single trial. It is also the clearest example of a narrow population. Mean symptom duration was under four months. People with years of symptoms were not in it. Neither were people with type 1 diabetes, or people whose neuropathy is not diabetic at all.

The smallest of the randomized trials

A 2011 single-blinded randomized controlled trial in the Singapore Medical Journal studied 30 feet from 24 patients. They were randomized to 12 daily infrared or sham treatments. Current perception threshold was measured by neurometer at 2,000 Hz, 250 Hz and 5 Hz, and checked again at six weeks and three months. No significant difference was found between the infrared and sham feet.⁸ The published report does not state a full exclusion list that we could obtain.

The other side of the argument

A 2023 systematic review in Current Diabetes Reviews took a wider view of photobiomodulation (light therapy aimed at cells) in diabetic peripheral neuropathy. It covered eight studies in people with type 2 diabetes. It reported less nerve pain (neuropathic pain) and better nerve conduction velocity. It also reported lower plantar pressure distribution (pressure across the sole). Its authors concluded that photobiomodulation is an effective, non-invasive option in this condition.⁹

That conclusion is real, and it belongs on this page. So does its basis. The review deliberately included both randomized and non-randomized studies,⁹ and uncontrolled designs are exactly where the placebo movement described above does its damage. It is a narrative synthesis, not a pooled estimate. It is limited to type 2 diabetes. A reader has every right to weigh it. A reader has no right to be told it settles the question.

Two independent groups have registered protocols for new systematic reviews in this area. One was published in BMJ Open in 2022 and one in PLOS ONE in 2024. Both call for randomized trials, with pain as a primary outcome. Their secondary outcomes include nerve conduction, sensation, quality of life and adverse events.^1,10 Protocols describe what a good answer would look like. They are not answers themselves. But two of them, registered fifteen years after a coverage determination, are a fair signal. Researchers consider the question open, not closed.

What the 2006 decision was actually based on

Coverage decisions are documents, and this one is public. Reading it is more useful than repeating its conclusion.

Before the analysis there was no national ruling on these devices. But local Medicare contractors for durable medical equipment already had the same non-coverage rules. In the peripheral neuropathy literature, the analysis found 14 studies. Of those, 11 had an infrared-only arm. Only three of those were placebo-controlled with a parallel group run at the same time. All three were double-blinded and used sham devices. They enrolled 18, 43 and 50 patients.³

The blinded treatment periods in those three trials were two weeks in one and four weeks in the other two. Between them they tested only two wavelengths, 890 and 905 nanometers. No investigator did dose-ranging (testing a range of doses) for energy density, dosing frequency or dosing length. None varied pulsatility or duty cycle. None checked whether any effect lasted long-term. None used hard clinical endpoints such as ulcer or amputation rates.³ The analysis stated that despite an exhaustive search it found no high-quality randomized phase III trials with hard clinical endpoints. It also stated that a major placebo effect ruled out confident reading of the many studies in which patients served as their own controls.³ It noted that two large trials were then in progress. They could not be reviewed because they were not yet complete or published.³

That is a defensible decision on that record. It is also a decision about three small, short, single-wavelength trials of a contact pad device.

What has changed since

Four of the six trials in the 2017 meta-analysis were published after the determination took effect.⁴ Trial lengths grew from four weeks to 90 days⁵ and to 12 weeks.⁷ Outcome measures widened from monofilament counts to nerve conduction velocity and quality of life.⁵ Then they widened to intraepidermal nerve fiber density on skin biopsy.⁷

The overall picture did not reverse. The pooled estimate for sensation is still null, with low certainty. The pain estimate does not favor infrared.⁴ The real additions on the other side are two. One is a symptom and quality of life signal without a structural change.⁷ The other is a narrative review reporting benefit from a mixed body of randomized and non-randomized studies.⁹

What has not changed

The coverage policy itself. The public record for national coverage determination 270.6 shows coding updates for ICD-10 in 2015 and 2017. The policy did not change. It states that the determination was last reviewed in November 2006.² Anyone who claims Medicare recently shifted its view on infrared for neuropathy is describing something that is not in the record.

Three research gaps also remain exactly where they were. There is still no phase III trial with hard clinical endpoints. There is still no dose-ranging study (one that tests a range of doses). No study has set what energy density, session length or course length would even be the right thing to test. And there is still no randomized trial of whole-body delivery in peripheral neuropathy at all — the pooled review excluded use on any region other than the feet, under its own eligibility rules.⁴

That last point needs saying carefully, because it is easy to abuse in both directions. A lack of trials of whole-body infrared is not evidence that whole-body infrared works. It is also not what the null pad-device results measured. It is a gap. A gap is a reason for modest expectations and honest conversation. It is not a reason for confidence either way.

The patients these trials did not study

Randomized trials earn their authority by controlling variation. They control it by choosing who gets in. That choice shows in this literature wherever the reports state it.

• A severity band. The 90-day home-use trial required a vibration perception threshold between 20 and 45 volts.⁵ Milder and more profound loss were both outside it.
• A region rule. The 2017 meta-analysis left out any trial that applied the treatment outside the feet, and any trial shorter than three days.⁴
• An early-symptom population. The nerve fiber density trial enrolled people with a mean symptom duration of 3.9 months. Their mean diabetes duration was 12.9 years, and all had type 2 diabetes.⁷
• One form of diabetes. The 2023 light therapy review (photobiomodulation) was limited to type 2 diabetes.⁹

For several of these trials we could not obtain the full eligibility and exclusion list from the publisher. In those cases we have not guessed at exclusions. This page does not claim any rule a report does not state.

What we can verify is what the designs did not test. None of these trials studied infrared in someone whose insulin resistance was being actively treated. None studied someone whose B12 deficiency had just been corrected, whose autoimmune driver had been found, or whose toxic exposure had been removed. None enrolled a person carrying several drivers at once alongside a long medication list. And every one of them tested infrared alone against a sham, on a fixed schedule, for a few weeks.

So a null result has limits. It came from a selected population, for one modality used by itself, over a short period. It tells you this device, at these settings, in these people, over this interval, did not beat sham on these measures. It does not show what happens in the patients who were screened out. And it does not describe a therapy used as one part of a plan instead of as the plan. That is the ordinary gap between efficacy under trial conditions and effectiveness in practice.

It cuts both ways, and we say so. The same logic that stops a null trial from closing the question also stops it from being a license to assume benefit. Where nobody has measured, nobody knows.

Does infrared heat improve circulation to the nerves?

There is a real reason clinicians care about heat and blood flow. It is separate from the neuropathy trials above.

What the heat therapy evidence shows

A 2021 systematic review and meta-analysis in Experimental Physiology pooled 15 studies of heat therapy. They covered healthy people and patients. Exposures ran 30 to 90 minutes over 10 to 36 sessions. Compared with control, heat therapy cut mean arterial pressure (average blood pressure) by 5.86 mmHg. It cut systolic blood pressure by 3.94 mmHg and diastolic blood pressure by 3.88 mmHg. It improved brachial artery flow-mediated dilatation (how well the arm artery widens) by 1.95%. Resting heart rate was unchanged. Certainty was rated moderate for the blood pressure outcomes. It was rated low for mean arterial pressure and flow-mediated dilatation.¹¹

Those are heart and blood vessel outcomes, from a body of work about heat therapy in general. Not one of them is a nerve measurement. They give a reasonable mechanistic reason to be interested in whole-body heat when neuropathy has a microvascular (small blood vessel) component. They are not evidence of nerve benefit. We do not present them that way, and neither should anyone else.

The vasa nervorum question

Peripheral nerves are fed by very small vessels, the vasa nervorum. The longest nerves in the body depend on the most fragile end of that supply. Oxygen delivery is a real bottleneck in metabolic neuropathy. That is why treatments that change local blood flow attract attention.

Warmth causes vasodilation (widening of blood vessels). That much is not in dispute. Whether raising whole-body temperature on a schedule produces a lasting change in nerve function is a different claim. It has not been shown in a randomized trial in this condition.

Metabolic stress

Infrared is sometimes described as modulating metabolic stress in nerve tissue. We have not found trial evidence testing that claim in people with peripheral neuropathy. So we do not make it. And we do not use it as a reason to delay the metabolic and nutritional work that does have evidence behind it.

Is infrared heat therapy safe if you have neuropathy?

This is not a theoretical concern and it is specific to heat.

Loss of feeling in diabetic peripheral neuropathy raises the risk of burns, injuries and foot ulceration (foot sores).¹² The mechanism is simple. The warning system that tells you something is too hot is the same system the disease has damaged. In the infrared studies themselves, the Medicare review noted that two patients in one trial got surface burns (superficial burns) under the device pads.³

That is why heat-based therapy in neuropathy belongs under clinical supervision. Skin is inspected before and after sessions. Session settings are set by someone who has measured how much sensation you have lost. And there is a low bar for stopping. It is also why a home device bought online carries a different risk from a supervised session, when the person using it cannot feel a burn forming.

Where whole-body infrared sits in a plan at Regenerve

Regenerve is directed by Dr. Gurpreet Singh Padda, MD, MBA, MHP. Whole-body infrared is one of the modalities available here. Others are class 4 photobiomodulation, class 3B cold laser, and metabolic and nutritional care. Electrodiagnostic testing (EMG/NCS) is done on site. VNG is a diagnostic test of inner-ear balance function, used when unsteadiness is part of the picture. It is a test, not a treatment.

None of it is prescribed before the driver is mapped. Peripheral neuropathy is a category, not a diagnosis. The order of steps matters more than the equipment list — a point covered in the hidden drivers of peripheral neuropathy.

What we tell patients about infrared specifically

We tell them the coverage status, so there is no billing surprise. We tell them the trial evidence is for a pad device on the feet. It is null on sensation over the lengths of time studied. The one trial measuring nerve fiber density found no structural change, while reporting symptom and quality of life benefit. We tell them no randomized trial has studied the whole-body form at all. We describe what we expect it to add — comfort, warmth, tolerance for the activity and metabolic work that carry the plan. And we say plainly that we are not claiming it repairs nerves.

We set a review point before starting. We agree on what would count as a change, and we stop if nothing changes. We do not promise that nerve damage can be regenerated or reversed. We publish no success rate for any Regenerve protocol.

“My ethos is to treat all of my patients as I would my own family, with the goal of giving them back their quality of life.” — Dr. Gurpreet Singh Padda, MD, MBA, MHP

Questions worth asking before starting a course

• Is this a contact pad device at a stated wavelength and dose, or whole-body radiant heat? The published trials are about the first one.
• How was the driver of my neuropathy found before this was recommended, and what tests were used?
• What outcome will be measured, with what instrument, and at what interval?
• How is my reduced ability to feel heat being accounted for in the protocol, and who inspects my skin?
• Is this being offered as one part of a plan, or as the plan?
• What is the review point, and at what stage do we stop?
• Am I signing an advance beneficiary notice, and what will I owe?

Start with the Nerve Damage Score

The Nerve Damage Score is five questions, and it is free. It points to which driver to chase first. That is the only thing that makes any decision about infrared meaningful.

Regenerve, 4477 Woodson Rd #104, St. Louis, MO 63134. Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. We are minutes from St. Louis Lambert International Airport and see patients from across the St. Louis region, Missouri and Illinois, including Edwardsville, Glen Carbon, Collinsville, Troy and Maryville.

Infrared is one of several in-clinic options. How PRP and BMAC fit for symptom relief is set out in orthobiologic injections for peripheral neuropathy.

Frequently asked questions

Is whole-body infrared therapy proven to treat peripheral neuropathy?

Not in the sense of a proven treatment. The randomized trials in this area studied contact pad devices on the feet and lower legs. A 2017 meta-analysis of six of them found a short-term gain in monofilament sensation that did not last, on low-certainty evidence. No randomized trial has tested whole-body delivery in peripheral neuropathy. So for that specific form there is an evidence gap, not a negative finding. Since 2006, Medicare has not covered infrared therapy devices for peripheral sensory neuropathy. So you pay out of pocket. We use it as supportive care inside a driver-directed plan, never as the treatment. See what we actually provide on site.

Does infrared help if my neuropathy is diabetic?

Diabetic peripheral neuropathy is driven by metabolic and microvascular (small blood vessel) injury. So the work that changes its course is metabolic. One 12-week sham-controlled trial in painful diabetic neuropathy reported symptom and quality of life benefit. It found no increase in nerve fiber density. That is a fair picture of what to expect: infrared may make you more comfortable while the metabolic work does the structural job. It does not replace that work. See diabetic peripheral neuropathy treatment in St. Louis.

Will infrared help if my neuropathy comes from a B12 deficiency?

It will not correct the deficiency, and correcting the deficiency is the point. Heat and light do nothing about absorption, intake, or the medications that interfere with B12. Infrared can sit alongside that correction for comfort. It cannot replace it. See functional B12 deficiency and neuropathy.

What about gluten-related neuropathy?

Same answer, different mechanism. If an immune reaction to gluten is driving the nerve injury, the treatment that matters is dietary and immune-based, not heat. Also note that people with non-diabetic drivers were not enrolled in the infrared trials at all. So there is no trial evidence either way for this group. See the gluten and neuropathy connection.

My nerve conduction study was normal but my feet still burn. Would infrared help?

A normal conduction study with ongoing burning points toward small fiber involvement. Standard nerve conduction testing often misses that. The next step is a workup matched to that pattern, not another modality, because a modality chosen before the driver is found is a guess. See small fiber neuropathy symptoms and testing.

Can infrared therapy reverse nerve damage?

We do not claim it can. The one trial that measured nerve fiber density found no structural change, even though patients reported better symptoms and quality of life. We use whole-body infrared for comfort, warmth and tolerance for the activity and metabolic work that carry the plan. We do not promise that nerve damage can be regenerated or reversed.

Is it safe to use a home infrared device for neuropathy?

It carries a different risk from a supervised session. Neuropathy damages the same warning system that tells you something is too hot, so a burn can form without being felt. In one infrared trial, two patients got superficial burns under the device pads. Under supervision, skin is inspected before and after sessions and settings match how much sensation you have lost.

Is whole-body infrared the same as infrared pads or laser therapy?

No. Whole-body infrared is a cabin that raises body temperature with radiant heat. Contact pad devices strap infrared diodes against the foot and lower leg. Those pads are what most neuropathy trials studied. Class 4 photobiomodulation and class 3B cold laser are separate modalities offered at Regenerve. Ask which one you are being offered, because studies of one do not describe the others.

Sources

1. Wang JY, Huang ZQ, Deng HP, Zhao L, Deng HY, Liu JP, Shen XY, Cheng K. Low level light therapy/photobiomodulation for diabetic peripheral neuropathy: protocol of a systematic review and meta-analysis. BMJ Open. 2022;12(9):e059476. pmc.ncbi.nlm.nih.gov
2. Centers for Medicare & Medicaid Services. National Coverage Determination 270.6, Infrared Therapy Devices. Effective October 24, 2006; implemented January 16, 2007. Medicare Coverage Database. cms.gov
3. Centers for Medicare & Medicaid Services. Decision Memorandum for Infrared Therapy Devices (CAG-00291N). Medicare Coverage Database. October 24, 2006. cms.gov
4. Robinson CC, Klahr PDS, Stein C, Falavigna M, Sbruzzi G, Plentz RDM. Effects of monochromatic infrared phototherapy in patients with diabetic peripheral neuropathy: a systematic review and meta-analysis of randomized controlled trials. Brazilian Journal of Physical Therapy. 2017;21(4):233-243. pmc.ncbi.nlm.nih.gov
5. Lavery LA, Murdoch DP, Williams J, Lavery DC. Does anodyne light therapy improve peripheral neuropathy in diabetes? A double-blind, sham-controlled, randomized trial to evaluate monochromatic infrared photoenergy. Diabetes Care. 2008;31(2):316-321. pubmed.ncbi.nlm.nih.gov
6. Clifft JK, Kasser RJ, Newton TS, Bush AJ. The effect of monochromatic infrared energy on sensation in patients with diabetic peripheral neuropathy: a double-blind, placebo-controlled study. Diabetes Care. 2005;28(12):2896-2900. pubmed.ncbi.nlm.nih.gov
7. Rastogi A, Uppula P, Saikia U, Bhansali A. Effect of monochromatic infrared energy on quality of life and intraepidermal nerve fiber density in painful diabetic neuropathy: a randomized, sham control study. Neurology India. 2021;69(5):1331-1337. pubmed.ncbi.nlm.nih.gov
8. Nawfar SA, Yacob NB. Effects of monochromatic infrared energy therapy on diabetic feet with peripheral sensory neuropathy: a randomised controlled trial. Singapore Medical Journal. 2011;52(9):669-672. pubmed.ncbi.nlm.nih.gov
9. Korada HY, Arora E, Maiya GA, Rao S, Hande M, Shetty S, Gundmi S, Anche P, Amravadi S. Effectiveness of photobiomodulation therapy on neuropathic pain, nerve conduction and plantar pressure distribution in diabetic peripheral neuropathy: a systematic review. Current Diabetes Reviews. 2023;19(9):e290422204244. pubmed.ncbi.nlm.nih.gov
10. Fan X, Yan G, Cao J, Zhao Y, Wang Y, Wang X, Mi J. Effectiveness and safety of photobiomodulation therapy in diabetic peripheral neuropathy: protocol for a systematic review and meta-analysis. PLOS ONE. 2024;19(8):e0308537. pmc.ncbi.nlm.nih.gov
11. Pizzey FK, Smith EC, Ruediger SL, Keating SE, Askew CD, Coombes JS, Bailey TG. The effect of heat therapy on blood pressure and peripheral vascular function: a systematic review and meta-analysis. Experimental Physiology. 2021;106(6):1317-1334. pubmed.ncbi.nlm.nih.gov
12. Tesfaye S, Selvarajah D. Advances in the epidemiology, pathogenesis and management of diabetic peripheral neuropathy. Diabetes/Metabolism Research and Reviews. 2012;28 Suppl 1:8-14. pubmed.ncbi.nlm.nih.gov

Whether your neuropathy gets worse depends far more on one thing than on the word “neuropathy” itself. Is the driver damaging your nerves still active? That is the whole answer. It is also why nobody can give you a timeline until the driver has been found.

Peripheral neuropathy is the most common reason for an outpatient neurology visit in the United States. It accounts for over $10 billion in health care spending each year.¹ Much of that reflects how long people live with a diagnosis that names the symptom, not the cause. Progression is not one fixed path, and it can be measured.

How does neuropathy progress?

When people say progression, they usually mean symptoms. But symptoms are only one of the things that change. Feeling, balance, strength and daily function can all shift, sometimes in different directions at once.

Length-dependent and symmetrical patterns

In many metabolic forms, the longest nerve fibers fail first. That is why symptoms usually start in the toes and move upward. It is also why the hands are often affected later, once the pattern has reached about mid-calf.

The pattern is also usually the same on both sides. That points toward a whole-body (systemic) driver. A one-sided or patchy pattern points somewhere else entirely. That is a useful thing for your clinician to notice early.

Small fiber involvement can progress when standard testing looks normal

Burning, hot-coal feelings and changed pain and temperature sense can be present while a routine nerve conduction study looks normal. That is because the study measures large fibers.

A normal result in that setting does not mean nothing is getting worse. It is a signal that the workup needs to match the symptom pattern, not stop.

What causes neuropathy to get worse?

Peripheral neuropathy is a category, not a diagnosis. These are the driver groups worth working through. More than one can be present in the same person.

Metabolic injury

When glucose runs high, sugars stick to proteins in a slow browning reaction. That makes advanced glycation end-products, which build up around the nerve. Poor flow through the small vessels that feed the nerve makes it worse. That is because the longest fibers depend on the weakest part of that supply.

The practical point: while the metabolic driver runs, injury goes on. That is true whether or not symptoms happen to be quiet that week. How strong the symptoms feel and how active the disease is are two different things.

Nutritional drivers

B12 deficiency can cause nerve damage that keeps getting worse. It keeps going until the deficiency is corrected. Diet, absorption after gut surgery, and drugs that interfere with absorption all belong in the history.

Autoimmune and immune-reactive patterns

Immune-driven processes can keep symptoms advancing while the immune activity goes on. Gluten-related nerve injury is one of them. These patterns are often the ones hiding behind an idiopathic (no known cause) label.

Toxic and medication-related exposures

Chemotherapy-related nerve injury follows the timeline of the exposure. So the history and the course of symptoms have to be read together. Heavy metals such as lead, arsenic and mercury are the other exposure group. They are worth ruling in or out when the history suggests it.

Structural compression

Not everything that looks like neuropathy is systemic. Sometimes symptoms follow the path of a single nerve. Then progression may be driven by pressure on the nerve (compression) and local inflammation instead. That responds to entirely different treatment. The difference is covered in nerve compression: carpal tunnel, sciatica and double-crush patterns.

How is neuropathy progression measured?

Progression is change over time. Change over time only means something against a baseline. Without one, every visit is a fresh guess about whether things are moving.

We perform electrodiagnostic testing (EMG/NCS) on site. It measures how large fibers carry signals. When unsteadiness, dizziness or falls are part of the picture, we use VNG as a diagnostic test of inner-ear balance function. It is not a treatment, and it does not measure peripheral nerves.

Metabolic and nutritional testing runs alongside both, because that is where most of the drivers you can change actually live.

Can neuropathy damage be reversed?

We do not promise that nerve damage can be regenerated or reversed. A plan aimed at the driver has a different goal, and one that is easier to defend. It finds what is still causing injury. It reduces that injury where it can be reduced. And it protects function.

Symptom treatment has a place inside that. Qutenza (capsaicin 8% patch) is FDA-approved in adults only for neuropathic pain from postherpetic neuralgia and from diabetic peripheral neuropathy of the feet. It is applied in clinic by a clinician and repeated no more often than every three months.

Orthobiologic injections such as PRP and BMAC are offered in selected situations. Better sleep and less pain are worth having in their own right. But neither one changes the driver.

When should worsening neuropathy be checked right away?

Some changes are worth acting on quickly instead of watching.

• Numbness that is spreading upward, or newly involving the hands.
• Pain that has started to disrupt sleep, or pain set off by light touch such as a bedsheet.
• New unsteadiness, dizziness, or any fall.
• Difficulty with stairs, weakness, or a foot that catches when you walk.
• Any break in the skin, blister, or hot, swollen foot when feeling is reduced.
• A high-risk history: diabetes, chemotherapy, known B12 risk, or a major exposure.

When protective feeling is reduced, checking your feet every day stops being optional. A numb foot no longer reports injury. So your eyes have to do the job the nerves used to do.

Start with the Nerve Damage Score

The Nerve Damage Score is five questions, and it is free. It is built to point at the driver most likely responsible in your case. That is the only honest starting point for a talk about whether things will get worse.

Regenerve, 4477 Woodson Rd #104, St. Louis, MO 63134. Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. We are minutes from St. Louis Lambert International Airport and see patients from across the St. Louis region, Missouri and Illinois, including Edwardsville, Glen Carbon, Collinsville, Troy and Maryville.

Frequently asked questions

My feet burn at night. Does that mean it is getting worse?

Not by itself. Nighttime burning is common early and does not reliably track severity. So how bad it is on a given night is a poor measure of progression. What matters is whether feeling, balance and function are changing over months. See small fiber neuropathy symptoms and testing.

How do clinicians predict whether neuropathy will progress?

By finding the driver and then watching whether it is still active. A driver that is being corrected and a driver that is left alone lead to very different paths in the same person. See the hidden drivers of peripheral neuropathy.

My blood sugar is under control now. Am I safe?

Better glucose control reduces one source of ongoing injury, but it is not the whole terrain. Lipids, blood pressure, small blood vessel health, nutrition status and any other driver all still matter. See diabetic peripheral neuropathy treatment in St. Louis.

What if nobody has found a cause for my neuropathy?

Idiopathic is a status, not a verdict. It usually means the workup stopped too soon, before the less common drivers were looked at. These include deficiency states, immune-reactive patterns and exposures. See functional B12 deficiency and neuropathy.

Could an exposure be making mine worse without my knowing?

It is possible, and it is worth ruling in or out instead of assuming. Heavy metals such as lead, arsenic and mercury are the classic example. Exposure history is often the only clue before testing. See heavy metals and neuropathy.

How do you stop neuropathy from progressing?

Find the driver that is still causing injury and reduce it where it can be reduced. That can mean correcting a B12 deficiency, getting metabolic injury under control, or removing a toxic exposure. A baseline from nerve testing lets your clinician see whether things are actually changing. Symptom treatment helps you feel better, but it does not change the driver.

Can neuropathy spread to the hands?

Yes. In many metabolic forms the longest nerve fibers fail first, so symptoms usually start in the toes and move upward. The hands are often affected later, once the pattern has reached about mid-calf. Numbness that newly involves the hands is one of the changes worth getting checked promptly instead of watched.

What’s the worst that can happen with neuropathy?

When protective feeling fades, a numb foot stops reporting injury. So a blister, a break in the skin or a hot, swollen foot can go unnoticed. Weakness, a foot that catches when you walk, new unsteadiness and falls are the other serious turns. Each one needs a prompt check. Daily foot checks become essential once feeling is reduced.

Sources

1. Tavee JO. Office approach to small fiber neuropathy. Cleveland Clinic Journal of Medicine. 2018;85(10):801–812. ccjm.org

Topical lidocaine and capsaicin 8% are the two topical options with the clearest evidence behind them for neuropathic foot pain. Which one fits depends on what is driving the neuropathy, not on how the burning feels. The American Academy of Pain Medicine brought together an expert panel. The panel reported strong evidence and high consensus that capsaicin 8% is effective for diabetic peripheral neuropathy and for postherpetic neuralgia (nerve pain after shingles). It also reported moderate evidence with high consensus that lidocaine is likely effective for diabetic peripheral neuropathy, idiopathic neuropathy and postsurgical neuropathy.¹

The other side matters just as much. A Cochrane review looked at topical lidocaine in adults with chronic neuropathic pain. It found only 12 studies covering 508 participants in total, all judged at high risk of bias. It concluded that there was no good-quality randomized evidence to support its use.² Topicals change the signal at the skin and nerve surface. They do not change what is damaging the nerve.

What to know before you try a topical

• Topicals modulate the signal, not the driver. The burning is an alarm. The alarm keeps ringing while the real problem goes on.
• The evidence is condition-specific. Support for lidocaine and for capsaicin 8% is tied to named diagnoses. It is not tied to “neuropathy” as a category.
• Peripheral neuropathy is a category, not a diagnosis. Metabolic, nutritional, autoimmune, toxic and structural drivers are often stacked in the same patient.
• Testing changes decisions. On-site electrodiagnostic testing (EMG/NCS) helps show which fibers are involved. That comes before a plan is built around a product.

How does topical lidocaine work on neuropathic foot pain?

Lidocaine is a local anesthetic (numbing drug). Put on the skin, it quiets the nerve endings under the area it covers. That can lower the burning or shooting pain in that patch of skin.

It does not reach the cause. It does not improve flow through the small vessels that feed the nerve. It does not correct a nutritional deficiency. It does not slow the metabolic chemistry that damaged the fiber in the first place.

Where the support is, and where it is not

The American Academy of Pain Medicine panel gave lidocaine its strongest rating for postherpetic neuralgia. There it found strong evidence and high consensus that lidocaine is effective. For diabetic peripheral neuropathy, idiopathic neuropathy and postsurgical neuropathy, the rating was lower. It was moderate evidence with high consensus that lidocaine is likely effective.¹

Read the Cochrane finding alongside that, not instead of it. Twelve small trials in 508 adults is a thin evidence base. Thin evidence is a reason to set expectations carefully. On its own, it is not a reason to rule out a low-risk option.² Your prescribing clinician decides whether a prescription or over-the-counter topical belongs in your plan.

When is the capsaicin 8% patch the right topical?

Capsaicin works through a different pathway than lidocaine, and its labeled use is narrower. Qutenza (capsaicin 8% patch) is FDA-approved in adults only for neuropathic pain from postherpetic neuralgia and from diabetic peripheral neuropathy of the feet.

The evidence rating tracks the label closely. The same expert panel found strong evidence and high consensus for capsaicin 8% in diabetic peripheral neuropathy and postherpetic neuralgia. It gave weaker ratings for other nerve pain conditions.¹

What “applied in clinic” means

At Regenerve, a clinician applies the capsaicin 8% patch. It is not sent home with you. It is not repeated more often than every three months.

That spacing is part of how the treatment is designed. It is one more reason the diagnosis has to be settled before the patch is scheduled. Our page on the Qutenza capsaicin 8% patch describes what the visit itself involves.

Why does the cause of your neuropathy decide which topical to use?

Patients often arrive with a list of creams, patches and counterirritants (products that create a competing sensation) found online. The list is not the problem. The problem is that it is built around the feeling, not the cause, so two people with the same burning end up on the same products for entirely different diseases.

We work the other way around. We start from which driver is doing the most damage right now.

• Metabolic pattern. Say the pattern and history fit diabetic peripheral neuropathy of the feet. Then both lidocaine and capsaicin 8% sit inside their evidence-supported ground. For capsaicin 8%, that ground is also FDA-labeled.
• Nutritional pattern. The history may point to B12 deficiency or a gluten-related process. Then a topical may make the nights easier while the real correction happens elsewhere.
• Chemotherapy-related pattern. Symptom tools may still have a role. But the priority is finding out whether large fiber, small fiber or mixed involvement is present.
• Autoimmune or structural pattern. Topicals alone are the weakest choice here. That is because inflammation and poor blood flow (impaired perfusion) keep the nerve irritable no matter what is on the skin.

Testing that changes the decision

Regenerve does electrodiagnostic testing (EMG/NCS) on site. It measures how large fibers carry signals. That helps separate a whole-body driver from a single pinched spot (focal compression). It also tells us whether the symptom picture and the wiring picture agree.

When unsteadiness or dizziness is also part of the story, VNG is available. VNG is a diagnostic test of inner-ear balance, not a treatment. It is used to find out whether the balance problem sits in the vestibular (inner-ear balance) system and not in the feet.

What to bring to your visit

Your clinician needs more than “it burns.” Pattern, timing and history are what narrow the list.

• Where it is: toes, forefoot, midfoot or the whole foot, and whether both sides are equally affected.
• When it is worst: especially whether it wakes you at night.
• What it feels like: burning, tingling, electric shocks, numbness, or pain from light touch, such as a bedsheet.
• Your history: diabetes or prediabetes, chemotherapy, and alcohol use. Also celiac or gluten sensitivity, weight-loss (bariatric) or other gut surgery, known B12 status, and any toxic exposures.
• What has already been tested: past EMG/NCS results, and whether anyone has raised small fiber involvement.

Start with the Nerve Damage Score

The Nerve Damage Score is five questions, and it is free. It is built to find which driver is most likely doing the damage in your case. That way the talk about topicals starts from a diagnosis, not a product list. We do not promise that nerve damage can be regenerated or reversed.

Regenerve, 4477 Woodson Rd #104, St. Louis, MO 63134. Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. We are minutes from St. Louis Lambert International Airport. We see patients from across the St. Louis region, Missouri and Illinois, including Edwardsville, Glen Carbon, Collinsville, Troy and Maryville.

When a topical alone is not enough, the next questions are usually about duloxetine for painful diabetic neuropathy or what to expect at a Qutenza patch visit.

Frequently asked questions

Is topical lidocaine worth trying for burning feet at night?

It is reasonable to discuss when your pain pattern matches a condition where lidocaine has support. It carries little whole-body risk. Treat it as symptom modulation. Pair it with a workup of what is driving the burning, because the relief stops when the patch does. See why feet burn at night.

Does topical lidocaine help diabetic peripheral neuropathy of the feet?

The American Academy of Pain Medicine panel rated lidocaine as likely effective for diabetic peripheral neuropathy. The rating rests on moderate evidence with high consensus. It does not address the metabolic and small-vessel injury underneath. That is where the rest of the plan goes. See diabetic peripheral neuropathy treatment in St. Louis.

Is the capsaicin 8% patch an option if my neuropathy is not diabetic?

Qutenza is FDA-approved in adults for postherpetic neuralgia and for diabetic peripheral neuropathy of the feet. Whether it fits another neuropathy depends on the driver your workup finds. A clinician applies it in the clinic. It is repeated no more often than every three months. See the hidden drivers of peripheral neuropathy.

Why do topicals help less when I have small fiber neuropathy?

Small fiber involvement causes burning, hot-coal feelings and changed temperature sense. These can be widespread, not limited to the patch of skin a topical covers. Standard nerve conduction studies may also look normal. That is why the workup has to match the symptom pattern. See small fiber neuropathy symptoms and testing.

Should I get nerve testing before trying a topical?

Not necessarily before, but testing changes what comes after. Electrodiagnostic testing shows which fibers are affected. That narrows the list of likely drivers. It also tells us whether a topical is a bridge or a distraction. See treatment options for peripheral neuropathy in the feet.

What is the most effective topical treatment for neuropathy in the feet?

Topical lidocaine and capsaicin 8% have the clearest evidence behind them. An American Academy of Pain Medicine expert panel rated capsaicin 8% effective for diabetic peripheral neuropathy on strong evidence. It rated lidocaine likely effective on moderate evidence. Which one fits your feet depends on what is driving the neuropathy, not on how the burning feels, so the cause gets found first.

Which is better for neuropathy, lidocaine or capsaicin?

Neither wins across the board. Lidocaine is a local anesthetic that calms the nerve endings under the skin it covers. Its support includes diabetic, idiopathic and postsurgical neuropathy. The capsaicin 8% patch works through a different pathway. It is FDA-approved only for postherpetic neuralgia and diabetic neuropathy of the feet. It is applied in the clinic no more often than every three months. Your diagnosis decides.

Is there a neuropathy cream that actually works?

Some topicals lower the burning in the patch of skin they cover. But the research is thinner than the store shelf suggests. A Cochrane review found only 12 studies of topical lidocaine, covering 508 adults, all at high risk of bias. A cream changes the signal at the skin. It does not change what is damaging the nerve, so it works best as one part of a plan built around the cause.

Sources

1. American Academy of Pain Medicine. Topical analgesics for neuropathic pain: an evidence-informed guide for the practicing clinician. Pain Medicine. 2026. AAPM clinical guideline summary
2. Derry S, Wiffen PJ, Moore RA, Quinlan J. Topical lidocaine for neuropathic pain in adults. Cochrane Database of Systematic Reviews. 2014. PMID 25058164

A VNG test, short for videonystagmography, measures a type of eye movement you cannot control, called nystagmus. It uses that to test how well your inner-ear balance system and the balance pathways in your brain are working.¹ It is a diagnostic test, not a treatment. It does not measure peripheral nerve function at all.

In someone who already has neuropathy, it answers one narrow and useful question. Is part of the unsteadiness coming from the vestibular (inner-ear balance) system, not from the nerves in the feet? That answer changes what the balance plan should look like.

How does a VNG test work?

A camera inside a pair of goggles records your eye movements. Meanwhile the examiner changes what you are looking at, where your head is, and the temperature inside your ear canal.

Brief nystagmus is normal as the eyes adjust when the head moves into certain positions. Nystagmus that shows up at other times may point to a disorder of the balance system in the inner ear. So may nystagmus that fails to show up when it should.¹

That is what makes it worth doing. Eye movement is involuntary, so the recording is an objective signal. That matters, because the symptom itself, feeling unsteady, is famously hard to describe.

What happens during a VNG test?

A VNG has three main parts. Each one checks a different part of the balance wiring.¹

• Ocular testing. You follow moving lights and hold your gaze on steady lights without moving your head.
• Positional testing. Your head and body are moved into different positions while the goggles watch for nystagmus.
• Caloric testing. Each ear is tested on its own. First it gets cool water or air, and then warm water or air in the same ear.

What the caloric portion is looking for

The cool temperature should make the eyes move in a certain way. The warm temperature should produce a different response.¹ Testing one ear at a time is what lets the two sides be compared.

Sometimes the eyes do not move as expected during caloric testing. That may mean there is damage in the inner ear or in the part of the brain that controls balance.¹ Abnormal VNG results are also associated with conditions such as benign paroxysmal positional vertigo, Ménière disease, labyrinthitis and vestibular neuritis.¹

Can neuropathy affect your balance?

Standing upright depends on three inputs. They are feeling from the feet and legs, vision, and the vestibular system. Peripheral neuropathy weakens the first one. If the third one is also impaired, the loss compounds. A person who could make up for one problem cannot make up for two.

Patients often describe both at once: numb feet and a swimming, off-balance feeling. It is easy for all of it to get blamed on the neuropathy. Testing separates them.

Balance can fail in more than one place at a time

Sorting this out is not academic. Vestibular findings call for one kind of rehabilitation. Sensory loss in the feet calls for another. That includes footwear, lighting, home hazards and the protective habits that matter when the feet no longer report injury.

Getting the proportions right is how a fall risk gets addressed, not just described.

What can a VNG test not tell you?

VNG does not identify your neuropathy driver. Peripheral neuropathy is a category, not a diagnosis. The cause may be metabolic, nutritional, autoimmune, toxic or structural. Finding out which happens elsewhere in the evaluation.

It also does not treat anything. A normal VNG is useful information. It moves the balance problem back toward the feet. But neither a normal nor an abnormal result is a therapy.

How it fits into an evaluation at Regenerve

Electrodiagnostic testing (EMG/NCS) is performed on site. It shows how well the peripheral nerves are conducting signals. VNG is used when balance, dizziness or past falls suggest the vestibular system may also be involved.

The two are read together, along with your symptom timeline, medications, and metabolic and nutritional workup. Our page on VNG balance testing covers what to expect on the day of the test itself.

Bring the details with you. When does the unsteadiness happen? Is it worse in the dark? Does the room spin, or do you just feel adrift? Have you fallen? Those details shape how the results are read.

Start with the Nerve Damage Score

The Nerve Damage Score is five questions, and it is free. It is the starting point for finding which driver is most likely damaging your nerves. That is the piece VNG cannot supply. We do not promise that nerve damage can be regenerated or reversed.

Regenerve, 4477 Woodson Rd #104, St. Louis, MO 63134. Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. We are minutes from St. Louis Lambert International Airport and see patients from across the St. Louis region, Missouri and Illinois, including Edwardsville, Glen Carbon, Collinsville, Troy and Maryville.

Frequently asked questions

What does VNG balance testing measure?

It records involuntary eye movements, called nystagmus, with infrared goggles. It uses the timing and conditions of those movements to assess the inner-ear balance system and the balance pathways in the brain. It is a diagnostic test, not a treatment. See our VNG balance testing page.

Is VNG the same as nerve testing for neuropathy?

No. VNG checks vestibular (inner-ear balance) function through eye movement. Electrodiagnostic testing (EMG/NCS) measures how peripheral nerves conduct. They answer different questions. They are often ordered together when both the feet and balance are involved. See the testing and care we provide on site.

Can VNG tell me why my feet are numb?

It cannot. Numbness in the feet is a peripheral nerve finding, and VNG does not measure peripheral nerves at all. What it can do is show whether some of your unsteadiness comes from a second problem in the inner ear. See peripheral neuropathy of the feet symptoms.

Why would someone with diabetes be sent for balance testing?

Because unsteadiness in diabetes is rarely one thing. Reduced feeling in the feet, vision changes and vestibular problems can all add up at once. The plan differs depending on which one is dominant. See diabetic peripheral neuropathy treatment in St. Louis.

What happens if my VNG is abnormal?

An abnormal result points to the vestibular system or the balance pathways in the brain. It guides the balance side of your care. It does not identify the driver behind your neuropathy, so that mapping still has to happen separately. See the hidden drivers of peripheral neuropathy.

Is a VNG test worth it if I have neuropathy?

It is when unsteadiness, dizziness or a fall is part of the story. Your eye movements during the test are involuntary. So the recording gives an objective signal for a symptom that is hard to describe. It shows whether part of your imbalance comes from the inner ear, not the feet. That changes which kind of balance rehabilitation you need.

What conditions can a VNG test find?

Abnormal VNG results are linked to inner-ear and balance-pathway problems. Examples are benign paroxysmal positional vertigo, Ménière disease, labyrinthitis and vestibular neuritis. The caloric portion tests one ear at a time, so the two sides can be compared. A VNG does not diagnose neuropathy or identify its cause. So nerve testing and the driver workup still happen separately.

What if my VNG test is normal?

A normal VNG is still useful. It tells your clinician the inner-ear balance system is not the main problem. That moves the explanation for your unsteadiness back toward the nerves in your feet. The plan then focuses on foot feeling: footwear, lighting, home hazards and the protective habits that matter when your feet no longer report injury.

Sources

1. MedlinePlus, National Library of Medicine. Videonystagmography (VNG). MedlinePlus Medical Test. Last updated June 28, 2023. medlineplus.gov

The Qutenza capsaicin 8% patch itself stays on for 60 minutes if you are being treated for postherpetic neuralgia. It stays on for 30 minutes if it is being applied to the feet for diabetic peripheral neuropathy.¹ Around that, expect skin marking and prep, and an optional numbing cream (topical anesthetic) beforehand. Your blood pressure is also checked during and after the application. The whole visit runs a good deal longer than the patch time.

Qutenza is applied by a clinician in the office. The label states plainly that it is not to be dispensed to patients for self-administration or handling, and that only physicians or health care professionals are to administer it.¹

What is Qutenza approved for?

Qutenza is indicated in adults for the treatment of neuropathic pain associated with postherpetic neuralgia and for neuropathic pain associated with diabetic peripheral neuropathy of the feet.¹ It is a TRPV1 channel agonist. It is not a general-purpose neuropathy patch.

Why the driver is established before the patch is considered

Peripheral neuropathy is mainly diagnosed clinically. That means through your history and a neurological check of small fiber feeling, large fiber feeling and ulcer risk.² Neuropathy is a category, not a diagnosis. So the first part of the visit finds which driver is causing your pain. It also checks whether the pattern matches an approved indication (approved use).

Regenerve performs electrodiagnostic testing (EMG/NCS) on site. Nerve conduction studies are indicated when there are atypical (unusual) clinical features. Examples are fast symptom onset, severe neuromotor impairment (major loss of nerve-driven muscle control) or feeling that is abnormal on one side more than the other.² If your history includes shingles, the background is on our page about postherpetic neuralgia and shingles nerve pain.

Want to learn more about nerve pain and the treatments we use? Get our neuropathy video series by email.

Before the patch: marking, preparation and the optional anesthetic

A physician finds the treatment area and marks it on the skin. That is the painful area, including spots of hypersensitivity and allodynia (pain from a light touch).¹ Hair may be clipped, not shaved, to help the patch stick. The area is washed with mild soap and water and dried well.¹

Pretreatment with a topical anesthetic is optional under the label. When it is used, it goes on the whole treatment area plus 1 to 2 cm around it. It stays on until the skin is numb (anesthetized). Then it is wiped off, and the area is washed again before the patch goes on.¹ There is no fixed numbing time. It runs until the skin is ready.

What to bring

• Your current medication list, including pain medicines and supplements.
• Any history of reaction to topical agents.
• Your blood pressure history, especially if it is unstable or poorly controlled.

What happens during a Qutenza treatment?

The patch is placed on the marked area and smoothed onto the skin. For diabetic peripheral neuropathy, it can be wrapped around the top, sides and sole of each foot (dorsal, lateral and plantar surfaces). That way it covers the treatment area completely.¹ A dressing such as rolled gauze may be used to keep it in contact. You are asked not to touch the patch or the treated area.

The recommended dose is up to four topical systems: 60 minutes for postherpetic neuralgia, 30 minutes on the feet for diabetic peripheral neuropathy.¹

How painful is Qutenza?

Expect burning and warmth in the treated area. The label is direct about this: even after a local anesthetic is used, patients may experience substantial procedural pain and burning during application and after removal, and clinicians are told to be prepared to treat that acute pain with local cooling or appropriate analgesic medication.¹

If you feel dizzy or otherwise unwell during the application, tell the clinician right away. Do not wait for the timer to finish.

Blood pressure monitoring

In clinical trials, transient increases in blood pressure occurred during or shortly after exposure to Qutenza. The changes averaged less than 10 mm Hg, though some patients had larger increases, and the changes lasted approximately two hours after removal.¹ That is why blood pressure is checked from time to time during and after the procedure.

Application-site reactions

Across all controlled clinical trials, the most common adverse reactions occurring in at least 5% of treated patients and more often than in controls were application site erythema, application site pain and application site pruritus.¹ In the postherpetic neuralgia trials, application site erythema occurred in 63% of patients treated with Qutenza compared with 54% of controls, and application site pain in 42% compared with 21%.¹

What happens after the Qutenza patch comes off?

The patch is removed slowly by rolling it inward, and cleansing gel is applied to the treated area and wiped off with dry gauze. Patients are advised that the treated area may be sensitive for a few days to heat — hot showers or baths, direct sunlight and vigorous exercise.¹

Contact the clinic if you develop anything beyond expected local sensitivity. The label carries specific warnings about severe application site burns and about reductions in sensory function, which are generally minor and temporary but are assessed before each subsequent application.¹

How often can you get a Qutenza treatment?

Treatment may be repeated every three months, or as warranted by the return of pain, and not more frequently than every three months.¹ That is a limit on how often, not a promise about how long relief lasts. How long any one patient goes between applications varies.

Where the patch sits in a larger plan

Qutenza acts locally on the pain signal in the treated skin. It does not address whatever is injuring the nerve. That is why the application is scheduled alongside driver-directed work, not instead of it.

At Regenerve, that work can include class 4 photobiomodulation, class 3B cold laser, whole-body infrared, and metabolic and nutritional care. Each is chosen to match the driver found during the evaluation. Orthobiologic injections (PRP and BMAC) are offered. When balance or dizziness is part of the picture, VNG (videonystagmography) may be used. It is a diagnostic test of inner-ear balance function. It is not a treatment.

Patch specifications

Each Qutenza topical system is 14 cm x 20 cm (280 cm²) and contains 8% capsaicin, 640 mcg per cm², for a total of 179 mg of capsaicin per system — 8% in the adhesive, 80 mg per gram of adhesive.¹ It can be cut before the release liner is removed to match the size and shape of the treatment area.¹

Being evaluated in St. Louis

Regenerve is at 4477 Woodson Rd #104, St. Louis, MO 63134, minutes from St. Louis Lambert International Airport, and is led by Dr. Gurpreet Singh Padda, MD, MBA, MHP. The practice serves the St. Louis region, Missouri and Illinois.

Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. Office hours are Monday through Thursday 9 a.m. to 4 p.m. and Friday 9 a.m. to 1:30 p.m.

Before scheduling anything, try the free Nerve Damage Score. It is a five-question assessment. It helps find which driver is behind your symptoms, and whether an approved indication even applies.

Frequently asked questions

How long does the Qutenza patch stay on?

Sixty minutes for postherpetic neuralgia. It is 30 minutes when applied to the feet for diabetic peripheral neuropathy, using up to four topical systems. The visit itself runs longer. That is because of marking, optional numbing time, removal, cleansing and monitoring. See our Qutenza capsaicin 8% patch page.

How often can Qutenza be repeated?

Every three months, or as warranted by the return of pain, and not more frequently than every three months. Whether a repeat application makes sense depends on your response. It also depends on whether your diagnosis still fits the approved indication. See diabetic peripheral neuropathy treatment in St. Louis.

What side effects are common?

Application site erythema, application site pain and application site pruritus are the most common reactions across controlled trials. Transient blood pressure increases averaging less than 10 mm Hg were seen during and shortly after treatment. That is why blood pressure is checked during the visit. See our neuropathy treatment FAQ.

Is Qutenza used for small fiber or idiopathic neuropathy?

Qutenza is labeled for adults with neuropathic pain from postherpetic neuralgia and from diabetic peripheral neuropathy of the feet. For small fiber or idiopathic neuropathy, the driver is worked up first. Then the treatment is matched to it. See small fiber neuropathy symptoms and testing.

Can I get the patch to use at home?

No. The label states that Qutenza is not to be dispensed to patients for self-administration or handling, and that only physicians or health care professionals administer it. Unintended capsaicin exposure can cause severe irritation of the eyes, mucous membranes, airway and skin. See the hidden drivers of peripheral neuropathy.

Do they numb the skin before Qutenza?

They can. A topical anesthetic before the patch is optional under the label. When it is used, it covers the whole treatment area plus 1 to 2 cm around it and stays on until the skin is numb. There is no fixed numbing time. It is then wiped off and the skin is washed again before the patch goes on.

Does Qutenza fix the nerve damage?

No. Qutenza acts locally on the pain signal in the treated skin. It does not address whatever is injuring the nerve. That is why the application is scheduled alongside driver-directed care, not in place of it. That care is chosen after the evaluation finds what is causing your neuropathy.

What should I avoid after a Qutenza treatment?

For a few days, the treated skin may be sensitive to heat. That means hot showers or baths, direct sunlight and vigorous exercise can make it flare. Contact the clinic if you notice anything beyond that expected local sensitivity. The label warns about severe burns at the application site. It also warns about reduced sensation, which is checked before any repeat treatment.

Sources

1. Averitas Pharma, Inc. QUTENZA (capsaicin) topical system — full prescribing information. Updated July 2026. DailyMed
2. Bodman MA, Dreyer MA, Varacallo MA. Diabetic Peripheral Neuropathy. StatPearls. StatPearls Publishing. 2024. NCBI Bookshelf NBK442009

The dividing line is what your legs are asking you to do. Restless legs syndrome produces an urge to move. It comes on at rest, gets worse in the evening and eases when you actually move. Peripheral neuropathy produces abnormal feelings: burning, numbness, tingling. Moving does not reliably relieve them. They usually start in the feet and work upward.

Both keep people awake, which is why they get confused. Between 5% and 15% of the population may have restless legs syndrome.¹ Peripheral neuropathy shows up with varying degrees of numbness, tingling, aching, burning, weakness of the limbs, hyperalgesia (extra pain from a painful trigger), allodynia (pain from a light touch) and pain.² At midnight, the overlap in how they feel is real. But the physiology underneath is not the same.

Why are restless legs and neuropathy so often confused?

The best evidence on this is a case-control study. It compared 245 patients with peripheral neuropathy to 245 controls of the same age and sex. Everyone was screened for restless legs syndrome with a standard questionnaire. It was based on international diagnostic criteria.³

On screening, 65 of the neuropathy patients (26.5%) came back positive for restless legs syndrome. So did 25 of the controls (10.2%). That looks like a large excess. But then a movement disorders specialist examined the patients who screened positive. The specialist did not know who had neuropathy. The diagnosis was confirmed in only 46% of the neuropathy group, compared with 80% of the controls.³

After that confirmation step, the overall rate of restless legs did not differ between the neuropathy patients and the controls: 12.2% versus 8.2%.³ The most common reasons for a false-positive screen were cramps and paresthesia (pins and needles). These lacked true day-night variation and did not get worse at rest.³

That is the practical lesson for anyone trying to name their own symptoms. Neuropathy feelings often answer “yes” to restless legs screening questions without meeting the actual criteria. Timing, and whether rest or movement changes it, are what separate them. In this group, a questionnaire on its own gets it wrong more often than not.

Where a real association was found

In the same study, 14 of 72 patients with hereditary (inherited) neuropathy had restless legs syndrome (19.4%). That rate was higher than in controls. It was also higher than in acquired neuropathy (9.2%).³ Neuropathy patients who did have restless legs more often had a family history of it. They were also younger, at an average of 49.9 years versus 61.4.³

Want to learn more about nerve pain and the treatments we use? Get our neuropathy video series by email.

How can you tell restless legs from neuropathy?

What does restless legs syndrome feel like?

• An urge to move the legs, usually with uncomfortable sensations.
• Triggered or worsened by rest, especially sitting or lying down.
• Worse in the evening and at night than during the day.
• Partly or fully relieved by movement, for as long as the movement continues.

What does peripheral neuropathy feel like?

• Burning, numbness, tingling or electric feelings, not an urge to move.
• Usually starts in the toes and feet and moves upward, evenly on both sides.
• Often worse at night, but walking does not reliably switch it off.
• May come with loss of protective feeling, balance changes or a changed walk.

The feet-first, even, both-sides spread is the most useful single clue. An urge that rest brings on and walking relieves is the other.

Neuropathy is a category, so the next question is which driver

Say the pattern points to nerve injury, not a movement disorder. Then the label “neuropathy” is only the halfway point. The driver can be metabolic, nutritional, autoimmune, toxic or structural. Each one changes what is worth doing.

Peripheral neuropathy is mainly diagnosed clinically. That means through your history and a neurological exam. Small fiber feeling is checked with temperature or pinprick. Large fiber feeling is checked with vibration. Ulcer risk is checked with 10 g monofilament pressure testing.² Nerve conduction studies and intraepidermal nerve fiber density testing (a skin biopsy) are called for when the case has unusual features. Examples are fast symptom onset, severe neuromotor impairment or feeling that is abnormal on one side more than the other.²

Testing we perform on site

Regenerve performs electrodiagnostic testing (EMG/NCS) in the office. That is the test used to assess large-fiber damage. When balance complaints or dizziness are part of the picture, VNG (videonystagmography) may be used. It is a diagnostic test of inner-ear balance function. VNG finds where a balance problem is coming from. It is not a treatment. Details are on our VNG balance testing page.

Can you have restless legs and neuropathy at the same time?

The two can coexist. A family history of restless legs plus a younger age at onset makes that more likely in someone who already has neuropathy.³ Finding one does not close the file on the other.

When both are in play, the plan has to treat the nerve driver and the urge-to-move pattern as separate problems. Treating only one leaves the other running at night.

What we do at Regenerve

Our approach targets the driver rather than the symptom. That means finding what is injuring the nerve before choosing anything. Then the plan is matched to it.

• Electrodiagnostic testing (EMG/NCS) performed on site.
• Class 4 photobiomodulation and class 3B cold laser.
• Whole-body infrared.
• Metabolic and nutritional care directed by the identified driver.
• Orthobiologic injections (PRP and BMAC).
• Qutenza (capsaicin 8% patch), FDA-approved in adults for neuropathic pain from postherpetic neuralgia and from diabetic peripheral neuropathy of the feet, applied in clinic by a clinician and repeated no more often than every three months.
• VNG balance testing, which is diagnostic only.

Surgery is not part of the treatment plan for peripheral neuropathy itself. Nothing here is offered as a way to reverse or regenerate nerve damage.

Being evaluated in St. Louis

Regenerve is at 4477 Woodson Rd #104, St. Louis, MO 63134, minutes from St. Louis Lambert International Airport, and is led by Dr. Gurpreet Singh Padda, MD, MBA, MHP. The practice serves the St. Louis region, Missouri and Illinois.

Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. Office hours are Monday through Thursday 9 a.m. to 4 p.m. and Friday 9 a.m. to 1:30 p.m.

If your legs keep you awake and you are not sure which of these you have, try the Nerve Damage Score. It is a free five-question assessment. It produces a large-print report you can bring to any doctor.

Frequently asked questions

Can restless legs syndrome feel like peripheral neuropathy?

Yes, and the confusion runs both ways. In one case-control study, 26.5% of peripheral neuropathy patients screened positive for restless legs. But the diagnosis was confirmed in only 46% of them. Cramps and paresthesia were the most common causes of a false positive. See burning feet and nerve pain.

How do clinicians tell them apart?

By timing and by what movement does. Think restless legs when an urge to move comes on at rest, peaks in the evening and eases while you walk. Think nerve injury when burning or numbness starts in the toes and spreads upward, evenly on both sides. See how to choose a neuropathy specialist.

Is burning at night more likely to be neuropathy?

Burning is a sensory symptom, not an urge to move. So it fits the neuropathy pattern more closely, especially small fiber damage. That does not rule out restless legs, since the two can coexist. See small fiber neuropathy symptoms and testing.

Does having neuropathy raise my risk of restless legs syndrome?

In hereditary neuropathy it did: 19.4% versus 9.2% in acquired neuropathy. But after the diagnosis was confirmed, the overall rate in neuropathy patients (12.2%) did not differ significantly from matched controls (8.2%). See the hidden drivers of peripheral neuropathy.

Will treating my diabetes help either problem?

Treating a metabolic driver targets the nerve injury. It does not target what drives the urge to move. So an urge-to-move pattern still needs its own assessment. Both should be named separately before a plan is built. See diabetic peripheral neuropathy treatment in St. Louis.

What could be causing my restless legs and sore feet?

It could be restless legs syndrome, peripheral neuropathy, or both. Think restless legs when rest brings on an urge to move that is worse in the evening and that walking relieves. Think nerve injury when burning, numbness or tingling starts in the toes, spreads upward on both sides and does not switch off when you walk.

How common is restless legs syndrome?

Between 5% and 15% of the population may have restless legs syndrome. One study looked at people with peripheral neuropathy. Confirmed restless legs showed up in 12.2% of them, compared with 8.2% of matched people without neuropathy. That difference was not significant. It was more common in hereditary neuropathy, at 19.4%.

Is there a test that tells restless legs and neuropathy apart?

Not a questionnaire alone. In the study above, a specialist’s exam confirmed the screening result in only 46% of neuropathy patients who screened positive. Neuropathy itself is diagnosed mainly from your history and a neurological (nerve) exam. Regenerve performs EMG/NCS nerve testing on site when the features call for it.

Sources

1. Mansur A, Castillo PR, Rocha Cabrero F, Bokhari SRA. Restless Legs Syndrome. StatPearls. StatPearls Publishing. Updated February 27, 2023. NCBI Bookshelf NBK430878
2. Bodman MA, Dreyer MA, Varacallo MA. Diabetic Peripheral Neuropathy. StatPearls. StatPearls Publishing. 2024. NCBI Bookshelf NBK442009
3. Hattan E, Chalk C, Postuma RB. Is there a higher risk of restless legs syndrome in peripheral neuropathy? Neurology. 2009;72(11):955–960. PMID 19038854

A skin punch biopsy counts the nerve fibers inside the epidermis (the top layer of skin). It reports that count as intraepidermal nerve fiber density, or IENFD. A low count is objective evidence that the small sensory fibers are damaged. These are the fibers that carry pain and temperature. They are the ones that cause burning feet while a standard nerve conduction study reads normal.

What the biopsy does not tell you is why those fibers are failing. That is the part that decides treatment. It comes from the rest of the workup, not from the number.

The test is used well beyond classic neuropathy cases. About 40% to 60% of patients with a fibromyalgia diagnosis show signs of small fiber neuropathy on skin punch biopsy.¹

Regenerve does the punch skin biopsy on site. The sample is taken during a clinic visit instead of being sent out.

How is a skin biopsy for small fiber neuropathy done?

A 3 mm punch is pressed into the biopsy site to take a small cylinder of skin, usually from the lower leg.¹ The sample goes to a lab. The lab stains the nerve fibers and counts how many cross into the epidermis per millimeter of tissue. That count is compared with normal values matched to site, age and sex.

It is a minor office procedure, not surgery. It samples the fibers directly instead of inferring (working out) their state from an electrical signal.

Want to learn more about nerve pain and the treatments we use? Get our neuropathy video series by email.

Why is my nerve conduction study normal if my feet burn?

Nerve conduction studies measure large myelinated fibers (fibers with a thick insulating coat). Small fibers have no coat or only a thin one. They do not add to that signal. So they can be badly damaged while the study reads normal.

Peripheral neuropathy is mainly diagnosed in the exam room. The doctor takes your history and checks your nerves. Small fiber sensation is tested with temperature or pinprick. Large fiber sensation is tested with vibration. Ulcer risk is tested with 10 g monofilament pressure testing.² Nerve conduction studies and intraepidermal nerve fiber density testing are called for when the case is unusual (atypical). Examples are fast symptom onset, severe nerve-and-muscle weakness (neuromotor impairment), or feeling that is abnormal on one side more than the other.²

Regenerve does electrodiagnostic testing (EMG/NCS) on site. We read it against the whole clinical picture instead of treating it as a verdict. A normal study in someone with burning feet is a reason to look at the small fibers, not a reason to stop looking.

How accurate is a skin biopsy for small fiber neuropathy?

By current normal values, the nerve fiber count in the skin (epidermal nerve fiber density) is abnormally low in only about two-thirds of patients thought to have small fiber neuropathy.³ That means roughly one in three patients with a convincing clinical picture will have a biopsy that reads normal.

Normal ranges, the sampling site and lab methods all shift where the line between normal and abnormal falls. A single number on its own is not a diagnosis. If your symptoms fit and the result is normal, that is a reason to widen the search, not to stop.

What each result changes

• Low IENFD. Small fiber damage is confirmed. The question moves entirely to which driver is producing it.
• Normal IENFD with fitting symptoms. The clinical picture still stands. Other or overlapping mechanisms get evaluated. The biopsy result is recorded, not used to dismiss the complaint.
• Normal IENFD with an atypical picture. The list of possible causes widens beyond small fiber involvement.

What causes small fiber neuropathy?

Neuropathy is a category, not a diagnosis. Small fiber damage can come from metabolic, nutritional, autoimmune, toxic or structural drivers. It is common for more than one to be active at the same time.

That is where the real work of the evaluation lives — finding which mechanism is doing the damage, then aiming treatment at it. Our discussion of the causes that most often get missed is in the hidden drivers of peripheral neuropathy.

Driver categories we work through

• Metabolic. How the body handles sugar, insulin resistance, and injury from glycation (sugar sticking to proteins).
• Nutritional. Trouble absorbing nutrients, and nutrient status. This includes after belly or weight-loss (bariatric) surgery.
• Autoimmune. Inflammation through the whole body, and the immune system attacking the body.
• Toxic. Medications, alcohol, chemo drugs and toxins in the world around you.
• Structural. Pinched nerves and mechanical causes that can sit on top of any of the above.

How is small fiber neuropathy treated at Regenerve?

At Regenerve the biopsy result feeds into a plan built around the cause we find. That plan can include class 4 photobiomodulation, class 3B cold laser, whole-body infrared, and metabolic and nutritional care.

Orthobiologic injections (PRP and BMAC) are offered. When balance complaints are part of the picture, VNG (videonystagmography) may be used as a diagnostic test of inner-ear balance function. It is not a treatment. Nothing offered here reverses or regenerates nerve damage, and no outcome is promised.

Questions worth asking before a biopsy

• What in my history makes small fiber damage the top suspect?
• Which site will be sampled, and which lab and normal values will be used?
• What will change in my evaluation if the result is low?
• What is the next step if the result comes back normal but my symptoms do not?

Being evaluated in St. Louis

Regenerve is at 4477 Woodson Rd #104, St. Louis, MO 63134, minutes from St. Louis Lambert International Airport, and is led by Dr. Gurpreet Singh Padda, MD, MBA, MHP. The practice serves the St. Louis region, Missouri and Illinois.

Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. Office hours are Monday through Thursday 9 a.m. to 4 p.m. and Friday 9 a.m. to 1:30 p.m.

If a nerve test came back normal and your feet still burn, start with the Nerve Damage Score. It is a free five-question assessment that produces a large-print report you can bring to any physician.

Frequently asked questions

What does a skin biopsy for small fiber neuropathy involve?

A 3 mm punch takes a small cylinder of skin, usually from the lower leg. A lab counts how many nerve fibers cross into the epidermis per millimeter. It is an office procedure, not surgery. See the testing and services we provide.

How is it different from an EMG and nerve conduction study?

Nerve conduction studies measure large myelinated fibers. The biopsy counts the small fibers directly. That is why you can have burning feet and a nerve conduction study that reads normal. See burning feet and nerve pain.

Can I have small fiber neuropathy if my biopsy is normal?

Yes. By current normal values, epidermal nerve fiber density is abnormally low in only about two-thirds of patients thought to have small fiber neuropathy. So a normal result does not rule out the diagnosis. See how to choose a neuropathy specialist.

If my biopsy is abnormal, what happens next?

The work shifts to finding which driver is damaging the fibers — metabolic, nutritional, autoimmune, toxic or structural. That is what decides treatment, not the density number itself. See how sugar damages nerves.

Is this test only relevant to diabetes?

No. Small fiber damage shows up with nutritional, autoimmune and toxic drivers as well. And roughly 40% to 60% of patients with a fibromyalgia diagnosis show signs of it on skin punch biopsy. See functional B12 deficiency and neuropathy.

What does IENFD mean on a biopsy report?

IENFD stands for intraepidermal nerve fiber density. The lab stains the skin sample. It counts how many small nerve fibers cross into the epidermis per millimeter of tissue. That number is compared with normal values matched to the biopsy site, your age and your sex. A low count is objective evidence that the small fibers carrying pain and temperature are damaged.

Who does skin biopsies for small fiber neuropathy in St. Louis?

Regenerve does the punch skin biopsy on site at 4477 Woodson Rd #104, St. Louis, MO 63134. The sample is taken during a clinic visit instead of being sent out. EMG/NCS nerve testing is also done in the same office. That lets us read both results against your history together.

What is the best treatment for small fiber neuropathy?

The one aimed at whatever is damaging the fibers. The biopsy confirms the damage but not the cause. So the driver comes first: metabolic, nutritional, autoimmune, toxic or structural. At Regenerve the plan can include class 4 photobiomodulation, class 3B cold laser, whole-body infrared, and metabolic and nutritional care. Nothing offered here reverses or regenerates nerve damage.

Sources

1. Kelley MA, Hackshaw KV. Intraepidermal Nerve Fiber Density as Measured by Skin Punch Biopsy as a Marker for Small Fiber Neuropathy: Application in Patients with Fibromyalgia. Diagnostics (Basel). 2021;11(3):536. PMID 33802768
2. Bodman MA, Dreyer MA, Varacallo MA. Diabetic Peripheral Neuropathy. StatPearls. StatPearls Publishing. 2024. NCBI Bookshelf NBK442009
3. Levine TD, Saperstein DS. Diagnosing Small Fiber Neuropathy Through the Use of Skin Biopsy. Practical Neurology. October 2009. practicalneurology.com

Two published trials have tested laser photobiomodulation in people who already have peripheral neuropathy. Both were run in neuropathy caused by chemotherapy. One compared a very low-power laser against a sham device. At twelve weeks, the laser group’s response rate held while the control group’s fell.¹ The other used a class 4 laser. It reported improvement in nerve score and walking distance, and it had no control group at all.² Neither reports nerve regeneration, reversal, or a cure. Neither enrolled patients whose neuropathy comes from diabetes or metabolic disease.

That is a thin evidence base. The honest thing to do with thin evidence is not to shrink from it. It is to read it carefully: what each trial measured, who it let in, who it kept out, and what its design was never built to answer. That is what the rest of this page does.

The short version

• Two trials, two very different lasers. The only sham-controlled trial used a class 2M laser rated in milliwatts. The only trial that used a class 4 laser had no control group.
• Dose is the variable, not the word “laser”. Wavelength, power density, energy density and treated area differ hugely between the two trials. Light therapy also has a documented biphasic dose response: a low dose can help more than a high one.³
• Order of events matters. In the sham-controlled trial, the control arm responded slightly more often at six weeks. The two arms pulled apart only at twelve weeks. That raises a question about how long a course needs to be.¹
• Both trials studied cancer survivors. Neither enrolled diabetic, nutritional, autoimmune or idiopathic neuropathy.
• The registered diabetic neuropathy laser trials screened out the harder patients. They screened out peripheral vascular disease, open wounds on the treatment area, and recent diabetic ketoacidosis. One protocol also screened out anyone who had taken gabapentin, pregabalin, tramadol or an opioid in the previous month.^4,5
• Coverage is a payer decision, not a clinical finding. The 2006 Medicare determination that gets quoted here is about infrared diode pads. It is not about laser photobiomodulation.⁶
• Map the driver first. Which mechanism is active decides whether light-based therapy belongs in the plan at all.

Does class 4 laser therapy work for neuropathy?

When people ask whether class 4 laser helps neuropathy, they usually mean one thing. Does laser light improve neuropathy symptoms in humans? The evidence base is real, but it is small. And it does not carry over evenly across neuropathy types.

Neuropathy is a category, not a diagnosis

The same burning-feet complaint can come from many places. It can be metabolic injury, a vitamin deficiency, a toxic exposure, chemotherapy, an autoimmune process, or a structural cause. Those are different diseases that happen to share a symptom.

A trial run in one of those groups says very little about the others. That is not a criticism of the trials. It is a statement about how far a trial in one defined group can be stretched to cover others.

What is a class 4 laser?

Laser safety classes run from 1 up to 4. They describe how dangerous a beam is to the eye and skin. They are a regulatory hazard rating. They do not tell you the wavelength, the power density at the tissue, the energy delivered, or the area treated. Those are the things that decide what happens in the body.

This matters more here than usual. The two published trials sit at opposite ends of that scale. The one with a control arm is the one at the bottom.

Dose is the variable that separates these trials

Both trials are described as photobiomodulation. In the light they actually delivered, they have almost nothing in common.

The parameters that define a photobiomodulation dose

A photobiomodulation dose has many parts. It is defined by wavelength, power, power density at the tissue surface, energy density (fluence), and the size of the treated area. It also depends on whether the beam is continuous or pulsed, how long each session lasts, and how many sessions are given over what period. Change any one of those, and you have changed the treatment.

The sham-controlled trial used a class 2M continuous-wave diode laser. It delivered 8 milliwatts through a 3.2 millimeter aperture (opening), applied point by point. There were sixteen points in the interdigital spaces (the gaps between fingers and toes) of the hands and feet. There were ten more points over the skin landmarks for the C6–T1 and L5–S1 nerve roots on both sides. The dose was 1 joule per point, rising to 2 joules per point in later sessions as tolerated. Treatment ran twice a week for six weeks.¹

The class 4 trial used a device that combined two diodes at 905 nanometers and 808 nanometers. One was pulsed and one was continuous. Peak powers were 25 watts and 1.1 watts. The power density was 0.168 watts per square centimeter. The beam spot was 150 square centimeters, covering the plantar surfaces of the hands and feet on both sides. The dose was set as an energy density of 6 or 8 joules per square centimeter. Treatment ran twice weekly for three weeks.²

Notice that the two doses are not even reported in the same units. One is joules per point at twenty-six separate points. The other is joules per square centimeter across a large field. There is no clean way to convert one into the other. That means the two trials cannot be pooled, compared, or averaged in any meaningful way.

The biphasic dose response

This is not a bookkeeping problem. It is the main reason results in this field disagree.

A 2009 review in the journal Dose-Response came from the Wellman Center for Photomedicine at Massachusetts General Hospital. It described a biphasic dose response seen again and again in low-level light therapy. Low levels of light stimulate and repair tissue better than higher levels do. The authors describe this pattern using the Arndt-Schulz curve.³ More is not better, and past a point more is worse.

The same review makes a point that bears directly on this page. Light therapy has many settings: wavelength, fluence, power density, pulse structure and treatment timing. Choosing among them rationally is hard. That difficulty has produced a body of research with both negative and positive studies.³ So a negative photobiomodulation trial can mean the therapy does not work. Or it can mean that particular dose did not work. From outside the trial, those two look identical.

So when you see mixed results in light therapy, do not conclude the field is unserious. Ask what dose was tested, in whom, and for how long.

The sham-controlled trial: 44 cancer survivors, 2022

This is the only randomized, sham-controlled trial of photobiomodulation in established neuropathy discussed here. It deserves a close reading, not selective quoting.

Who was studied

Teng and colleagues published in Supportive Care in Cancer. They enrolled 44 cancer survivors who still had neuropathy symptoms. Each was at least three months past finishing potentially neurotoxic chemotherapy (chemotherapy that can damage nerves). Participants were randomized 2:1, with 29 to laser and 15 to sham. They were treated twice weekly for twelve sessions over six weeks. Assessments came at baseline, six weeks and twelve weeks.¹

The group was 61 percent female, with a mean age of about 62. Just under half had colorectal cancer, and about a third had breast cancer. On average, roughly fifteen months had passed since chemotherapy. Neuropathy was grade 1 in 64 percent and grade 2 in 36 percent. That is mild to moderate.¹

Who was screened out

The trial listed six specific exclusions. They are worth reading as a description of who was not in the room.¹

• Anyone unable to lie flat on their back (supine) for a thirty-minute period.
• Anyone with an open wound or ulcer over the treatment area.
• Anyone with a clinical diagnosis of peripheral neuropathy from another cause. The paper notes that diabetes without neuropathy was not itself an exclusion. But diabetes with neuropathy was, because that is a second cause.
• Anyone with uncontrolled psychiatric illness or cognitive dysfunction (problems with thinking or memory) that could get in the way of completing assessments.
• Anyone with a life expectancy under three months.
• Anyone using a concurrent complementary therapy for neuropathy during the study.

Read together, this describes a fairly well, fairly mobile group. They had one identified cause of neuropathy, intact skin on the feet, no other treatments running alongside, and mild to moderate severity. That is a clean trial population. It is not the population that walks into a neuropathy clinic. That patient has type 2 diabetes, an old foot ulcer, three prescriptions for nerve pain and fifteen years of symptoms.

What the response rates showed, and in what order

At six weeks, response rates were 48 percent in the laser group and 53 percent in the sham group. At twelve weeks, they were 45 percent and 33 percent, in the same order.¹ In plain terms, the sham group responded slightly more often at the end of treatment. The two arms pulled apart only at follow-up. The laser group held its gains, and the control group’s declined.

That finding must stay on the page. It also has to be read with three facts attached.

First, this was a non-comparative trial by design. Each arm was tested against a fixed statistical threshold. It was not tested against the other arm. The published null hypothesis was that the true response rate is 5 percent. The sample size was set to give 80 percent power if the true response rate on treatment were 20 percent.¹ The authors state plainly that the design did not allow a statistical comparison between the treatment and control arms.

Second, the control arm had fifteen people in it. In an arm of fifteen, one person is worth about seven percentage points. So the five-point gap at six weeks is smaller than a single person’s response.

Third, the laser arm’s response rate did beat the trial’s preset threshold at both time points. Reported side effects were low grade.¹ The authors’ own conclusion is measured. They say the result warrants evaluation in a properly powered phase III trial.

Why a sham arm is hard to build in a light-therapy trial

The paper describes its sham honestly. Sham patients got the same visit schedule and the same eye mask. They got the same equipment and the same application points. An opaque aluminum cover blocked the laser aperture. That way the sensory experience would match the active treatment.¹ That is a careful design. And with a device delivering 8 milliwatts, there is little heat or sensation to give the difference away.

Blinding was still incomplete, and the authors say so. The trial was single-blinded. The physician investigator who did the clinical neuropathy assessment was unblinded. The paper’s own list of limitations names the unblinded clinical assessor and therapist as a weakness.¹ An unblinded assessor knows which group a patient is in. That can shift a clinician-rated score in either direction.

None of this is a reason to discount the trial. It is a reason to hold both arms’ numbers loosely, including the six-week ones.

What this design could not capture

The authors list the limitations themselves. The sample was small, and the treatment period was short. The assessor and therapist were unblinded. COVID-19 restrictions caused unavoidable delays to study visits. The authors also note that no neurophysiological testing (nerve testing) was done because of limited resources. They suggest it as an objective measure for a future trial.¹

Three more things follow from the design, not from any fault in it. First, the trial tested laser alone. So it cannot say anything about laser used alongside metabolic correction, nutritional repletion (restoring missing nutrients) or exercise. Second, follow-up stopped at twelve weeks, which is six weeks after the last session. Nothing in it speaks to how long results last beyond that. Third, there was no nerve conduction testing. So the trial measured symptoms and function, not the nerve itself.

The NEUROLIGHT pilot trial: 60 patients, a class 4 laser, 2026

The second trial is the one that actually used a class 4 device. It is a pilot (a small early study) without a control group.

Who was studied

Claes and colleagues published in Lasers in Medical Science. They treated 60 cancer patients with chemotherapy-induced peripheral neuropathy. The work took place at Jessa Hospital in Hasselt, Belgium, between February 2022 and November 2023. Twenty-eight received six sessions at 6 joules per square centimeter. And thirty-two received six sessions at 8 joules per square centimeter. Both groups were treated twice weekly over three weeks.²

Most participants were women, with mean ages around 61 to 64. Breast cancer was the most common primary cancer. Next came colorectal, head and neck, ovarian, endometrial, bladder, lung and prostate.²

Who was screened out

The entry rules were narrower than they first appear. A patient needed a physician diagnosis of chemotherapy-induced neuropathy. They had to be at least 18. They had to have had one of a specific list of neurotoxic agents: paclitaxel, docetaxel, oxaliplatin, cisplatin, thalidomide, bortezomib or vincristine. The last dose had to be at least two weeks earlier. And they needed a Fitzpatrick skin type between I and V.²

That last rule excluded Fitzpatrick type VI, the most deeply pigmented skin. Pigment absorbs light. So this is a real limit on who the reported doses have been tested in.

The stated exclusions were two. One was skipping more than two treatment sessions in a row. The other was having neuropathy symptoms before receiving chemotherapy.² That second one is the important one. It removes exactly one kind of patient. That patient arrives at a neuropathy clinic with pre-existing diabetic or idiopathic (no known cause) neuropathy that chemotherapy then made worse. That is a common and difficult case, and this trial cannot speak to it.

What moved and what did not

The modified Total Neuropathy Score improved significantly over time (P = 0.048). So did the six-minute walk test (P < 0.001). Walking distance improved about 13 percent in the lower-dose group and about 18 percent in the higher-dose group. Pain scores on the numeric rating scale improved over time (P < 0.001), with better scores in the lower-dose group (P = 0.034). Patient satisfaction improved (P = 0.003). No adverse events were reported.²

Not everything moved. There was no significant change in the FACT/GOG-NTX total score or in its neurotoxicity subscale. That means the broader quality-of-life questionnaire did not pick up the same signal.²

That split between a walking test and a questionnaire is common in neuropathy research. It is a practical reason to track what you can do, such as how far you can walk and how steady you are. One overall score is not enough.

Note also that the lower dose, not the higher one, produced the better pain scores. On that basis, the authors decline to name an optimal fluence.² That is the biphasic dose response showing up inside a single trial.

What this design could not capture

The central limitation is built into the design. Both groups received photobiomodulation, and there was no sham arm. So improvement over time cannot be separated from natural recovery. Nor can it be separated from regression to the mean (extreme scores drifting back toward average) or from a placebo effect. The authors say this plainly. They accept that a placebo effect could partly explain the results.²

The authors also report that the sample was too small to sort results by key factors. These included chemotherapy type, number of cycles, and time since chemotherapy ended. They also included prior lines of neurotoxic treatment and neuropathy-inducing comorbidities (other conditions) such as diabetes. The effect of other drugs taken at the same time, like duloxetine and pregabalin, was not assessed.² In other words, the trial could not tell you whether a diabetic patient in the group did better or worse than a non-diabetic one.

Twenty of the sixty patients were lost to follow-up, twelve in the lower-dose group and eight in the higher-dose group.² That is a third of the sample. It is one more reason to read the later time points with caution.

How long does a course need to be?

The timeline in the sham-controlled trial is the most useful thing on this page. The laser arm did not lead at six weeks. It led at twelve.¹

Two readings are possible, and the trial cannot tell them apart. Either the laser effect takes longer to appear than a treatment course lasts. Or the control group’s early response was a short-lived placebo response that faded on schedule, while the laser group’s did not. Both fit the numbers.

Either way, the practical lesson is the same. Judging a course of photobiomodulation the moment the last session ends is judging it too early. It also makes follow-up length a fair question to ask of any trial in this field. The sham-controlled trial stopped at twelve weeks. The class 4 pilot collected data at baseline, after the six sessions, three weeks later, and again at six months and one year. But with no control arm, its long-term numbers cannot be credited to the laser.^1,2

Does laser therapy work for diabetic neuropathy?

Diabetic peripheral neuropathy is the clearest gap in this evidence. Neither trial above enrolled that population. The mechanisms also differ. Metabolic and microvascular injury (damage to the tiny blood vessels) varies from patient to patient. A single fixed protocol is unlikely to address that evenly. Several of those drivers are covered in our review of the hidden drivers behind peripheral neuropathy.

Two registered sham-controlled trials, and what they excluded

Laser trials in diabetic neuropathy have been registered and run. Two sham-controlled trials of the same device were registered on ClinicalTrials.gov. The device was a 635-nanometer, three-diode, 17-milliwatt laser. Both trials applied it fifteen minutes per foot, twice weekly for six weeks.^4,5

The first was completed with 30 participants.⁴ The second was terminated after enrolling 18, because it could not recruit. Summary results are posted on its registry record.⁵ Neither is a peer-reviewed publication, and neither is large enough to settle anything. What they do record precisely is who was allowed in.

Both protocols required foot pain that was chronic, bilateral (in both feet), and roughly the same on each side. The pain had to be rated at least 50 on a 0–100 visual analog scale. Patients also had to be on a stable diabetes medication plan for the preceding 30 days.^4,5

The exclusions are the striking part. Across the two records, people were excluded for any of the following:^4,5

• Foot pain that was unilateral or noticeably different between the two feet.
• Pain rated below 50 on the visual analog scale — that is, milder cases.
• Foot pain not clearly linked to diabetes, or linked to diabetes plus something else.
• Serious organ disease or other serious primary disease.
• Diabetic ketosis, ketoacidosis or severe infection within the previous two weeks.
• An active chronic pain condition. The second record names chronic fatigue syndrome, fibromyalgia, endometriosis, inflammatory bowel disease, interstitial cystitis and peripheral vascular disease.
• Cancer, or treatment for cancer, in the previous six months.
• An active infection, wound or other external trauma anywhere on the treatment area.
• Previous surgery or an implanted device for diabetic neuropathy foot pain.
• Analgesics or NSAIDs within seven days. Antidepressants within 30 days. Gabapentin, pregabalin, tramadol or opioid medicines within 30 days. Local anesthetic injections within 30 days.
• Ongoing litigation or disability benefits related to the study parameters.

Why that matters for a patient with metabolic disease

Line those rules up against a real clinic waiting room. A patient with peripheral vascular disease is out. A patient with a healing ulcer is out. A patient whose neuropathy is part metabolic and part something else is out. A patient with fibromyalgia alongside their neuropathy is out. A patient on gabapentin or pregabalin is out unless they stop for a month. That is a large share of people who have been treated for painful neuropathy. A patient whose pain is bad in one foot and mild in the other is out.

This is not sharp practice by the investigators. Trials are built this way on purpose, to cut noise and isolate a single effect. But it has a consequence that gets skipped over all the time. A modest or null result in such a tightly selected group does not establish that the treatment fails in the patients who were screened out. It establishes what happened in the patients who were let in.

The patients screened out here had vascular disease, unstable glycemic control (blood sugar control) or open wounds. Others had several pain conditions, polypharmacy (many medicines at once) or mixed causes. They are exactly the patients a metabolic neuropathy practice sees most days. The evidence is truly silent about them. Silence is not a negative finding. It is not a positive one either.

Does Medicare cover laser treatment for neuropathy?

A national coverage determination in effect since October 24, 2006 states that infrared therapy devices are not covered by Medicare for treating diabetic or non-diabetic peripheral sensory neuropathy, or wounds or ulcers of the skin and subcutaneous tissues, including for pain arising from those conditions.^6,7

The determination is specific about what it is describing. It defines an infrared therapy device as an array of juxtaposed infrared diodes affixed to a flexible pad held in contact with the skin, which can also produce local warming as a secondary effect.⁶ That is a different piece of equipment from a laser, and the determination was written about the evidence for those pad devices.

It is a payer decision about a device category. It is not a clinical conclusion about laser photobiomodulation. It should not be read as either an endorsement or a verdict. Because it dates from 2006, it also predates both trials on this page. Local coverage rules may differ. Nothing here is a benefits determination for any individual.

Where a service is not covered, patients sign an Advance Beneficiary Notice before it is provided. That way the financial side is settled in writing in advance, not discovered afterward. It is fair to ask any clinic which device it is using. It is also fair to ask which coverage language it is relying on.

How light-based therapy fits into an evaluation-first plan

Class 4 photobiomodulation, class 3B cold laser, and whole-body infrared are offered here. They are part of a plan built around whichever driver the evaluation identifies. They are not offered as nerve regeneration or reversal, and no success rate is published for them.

Before any of it is discussed, the evaluation looks for which mechanism is active. Electrodiagnostic testing (EMG/NCS) is performed on site. VNG (videonystagmography) is also available. It is a diagnostic test of inner-ear balance function, used when dizziness or unsteadiness is part of the picture. It is a test, never a treatment.

The published trials tested light on its own. That is the only way to isolate its effect, but it is not how neuropathy is usually treated. Here, light-based therapy sits alongside metabolic and nutritional care aimed at the driver itself. That combination has not been tested in a randomized trial. Saying so is more useful than implying it has.

Orthobiologic injections (PRP and BMAC) are offered here as well.

What all of this adds up to is a conversation, not a protocol. The risks of photobiomodulation reported in these trials were low: mild, low-grade events in one and none in the other. The potential benefit in a patient like you is truly uncertain. Both halves of that picture belong in the discussion before anyone starts a course of treatment.

What to ask before you commit to a course of treatment

• Which neuropathy driver do you believe is dominant in my case, and what did you base that on?
• Is the plan supported by trial evidence in a population like mine, or extrapolated from a different one?
• If it is extrapolated, what specifically about my case makes you think it transfers?
• How many sessions, over what period, at what wavelength and what energy density?
• When will we judge whether it is working, and why then rather than at the last session?
• What function will we measure, not just what pain score?
• Which device is this, what class is it, and what coverage language applies to it?

Where we are and how to start

Regenerve is located at 4477 Woodson Rd #104, St. Louis, MO 63134, minutes from St. Louis Lambert International Airport, and we see patients from across the St. Louis region, Missouri and Illinois. You can call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com.

The free Nerve Damage Score is a five-question starting point for the driver question. That is the question that decides whether light-based therapy belongs in your plan at all.

Both laser trials enrolled people treated with chemotherapy. So chemotherapy-induced peripheral neuropathy (CIPN) is the closest match to their results. The injection-based option in the same plan is covered in orthobiologic injections for peripheral neuropathy.

Frequently asked questions

Is the evidence for photobiomodulation in neuropathy strong enough to rely on?

On its own, no. There are two published trials in established neuropathy, both in chemotherapy-induced cases. One is small and sham-controlled, and one has no control group at all.^1,2 That is a reason to treat it as one part of a plan aimed at an identified driver, not as the plan. It is not a reason to call it disproven, because the trials that exist have not studied most of the people asking the question. See the treatments offered here.

Does that evidence transfer to diabetic neuropathy?

Not automatically. Diabetic peripheral neuropathy involves metabolic and microvascular (small blood vessel) drivers. These vary between patients. Neither published trial on this page enrolled that population. Registered diabetic neuropathy laser trials do exist. But they excluded peripheral vascular disease, open wounds on the feet, and recent ketoacidosis. They also excluded patients taking common nerve pain medications. So they say little about a complex metabolic patient either.^4,5 See how diabetic peripheral neuropathy is approached here.

The sham group did better at six weeks. Does that mean the laser did nothing?

It means the trial did not show a laser advantage at the end of treatment, which is worth knowing. It does not mean nothing happened, for three reasons. First, the trial was designed as non-comparative, and its authors state it could not statistically compare the arms. Second, the control arm had only fifteen people, so a five-point gap is smaller than one participant’s response. Third, by twelve weeks the laser group had held its response while the control group’s had fallen.¹ See which specialist to see when neuropathy has not improved.

How is photobiomodulation different from Qutenza?

They are unrelated mechanisms with very different evidence. Qutenza (capsaicin 8% patch) is FDA-approved in adults only for neuropathic pain from postherpetic neuralgia and from diabetic peripheral neuropathy of the feet. It is applied in clinic by a clinician, never dispensed for home use, and repeated no more often than every three months. See how Qutenza is used in clinic.

Will Medicare cover light therapy for neuropathy?

A national coverage determination in effect since October 2006 makes infrared therapy devices non-covered for peripheral sensory neuropathy, wounds and ulcers.⁶ That determination describes arrays of infrared diodes on a flexible pad. It does not describe laser photobiomodulation. And coverage is a payer decision, not a statement about whether something works. Where a service is not covered, an Advance Beneficiary Notice is signed before treatment. Contact us with coverage questions.

Can laser therapy reverse neuropathy?

No published trial shows that. Neither of the two trials in established neuropathy reports nerve regeneration, reversal or a cure. That is why light-based therapy is not offered here as nerve regeneration or reversal. No success rate is published for it. It is used alongside metabolic and nutritional care aimed at whatever driver the evaluation finds.

What are the side effects of class 4 laser therapy?

In the published trials, very few. The class 4 pilot trial in 60 patients reported no adverse events, and the sham-controlled trial reported only mild, low-grade side effects. One limit matters: the class 4 trial excluded the most deeply pigmented skin, Fitzpatrick type VI. Pigment absorbs light, so the reported doses have not been tested in that skin type.

How many laser sessions does neuropathy treatment take?

The two trials used different schedules: twelve sessions over six weeks with a low-power laser, and six sessions over three weeks with a class 4 laser. In the sham-controlled trial, the laser group did not pull ahead until twelve weeks, six weeks after the last session. So a course should not be judged the day it ends. Ask when progress will be measured, and why then.

What are the drawbacks of laser therapy for neuropathy?

The main drawback is a thin evidence base. Only two trials have tested it in established neuropathy, both in people whose nerve damage came from chemotherapy. The class 4 trial had no control group and lost a third of its patients to follow-up. Neither trial enrolled diabetic neuropathy. Medicare does not cover infrared pad devices for neuropathy, though that rule was not written about lasers.

Sources

1. Teng C, Egger S, Blinman PL, Vardy JL. Evaluating laser photobiomodulation for chemotherapy-induced peripheral neuropathy: a randomised phase II trial. Supportive Care in Cancer. 2022;31(1):52. https://pmc.ncbi.nlm.nih.gov/articles/PMC9758032/ (44 cancer survivors at least 3 months after neurotoxic chemotherapy; randomized 2:1, 29 laser and 15 sham; class 2M continuous diode laser, 8 mW through a 3.2 mm aperture, 1–2 J per point at 26 points, twice weekly for 12 sessions; response rates 48% laser and 53% sham at 6 weeks, 45% and 33% at 12 weeks; non-comparative design; null hypothesis of a 5% true response rate; sham delivered with the aperture occluded by an opaque aluminum cover; limitations include small sample, short intervention period and unblinded clinical assessor and therapist).
2. Claes M, Lodewijckx J, Robijns J, Hermans S, Peeters P, Mebis J. Evaluating the efficacy of photobiomodulation therapy in the management of chemotherapy-induced peripheral neuropathy: a pilot trial (NEUROLIGHT trial). Lasers in Medical Science. 2026;41(1):57. https://pmc.ncbi.nlm.nih.gov/articles/PMC12988979/ (60 cancer patients with chemotherapy-induced peripheral neuropathy at Jessa Hospital, Hasselt, Belgium, February 2022 to November 2023; class IV MLS M6 laser, 905 nm and 808 nm, peak power 25 W and 1.1 W, power density 0.168 W/cm², 150 cm² beam spot; 6 sessions at 6 J/cm² (n = 28) or 8 J/cm² (n = 32); Fitzpatrick skin types I–V only; exclusions were interruption of more than two consecutive treatments and neuropathy symptoms preceding chemotherapy; mTNS P = 0.048, 6MWT P < 0.001, NRS pain P < 0.001 favoring the 6 J/cm² group P = 0.034, no significant difference in FACT/GOG-NTX total score or neurotoxicity subscale; no control group; 20 of 60 lost to follow-up).
3. Huang YY, Chen AC, Carroll JD, Hamblin MR. Biphasic dose response in low level light therapy. Dose-Response. 2009;7(4):358–383. https://pmc.ncbi.nlm.nih.gov/articles/PMC2790317/ (low levels of light stimulate and repair tissue more effectively than higher levels, described by the Arndt-Schulz curve; the difficulty of choosing among wavelength, fluence, power density, pulse structure and treatment timing has produced both negative and positive studies).
4. ClinicalTrials.gov. Study of Low Level Laser Therapy to Treat Diabetic Peripheral Neuropathy Foot Pain (NCT02461225). Erchonia Corporation. https://clinicaltrials.gov/study/NCT02461225 (double-blind, placebo-controlled randomized evaluation of the Erchonia FX-635; completed with 30 participants; three 17 mW 635 nm diodes, 15 minutes per foot, twice weekly for 6 weeks; full inclusion and exclusion criteria as summarized above).
5. ClinicalTrials.gov. An Evaluation of the Effect of Low Level Laser Therapy on Diabetic Peripheral Neuropathy Pain (NCT04006392). Erchonia Corporation. https://clinicaltrials.gov/study/NCT04006392 (double-blind, placebo-controlled randomized evaluation of the Erchonia FX-635; terminated for inability to recruit after enrolling 18 participants; results posted March 14, 2023; exclusions include peripheral vascular disease, active infection or wound on the treatment area, serious organ disease, and recent diabetic ketosis or ketoacidosis).
6. Centers for Medicare & Medicaid Services. National Coverage Determination 270.6: Infrared Therapy Devices. Effective October 24, 2006. https://www.cms.gov/medicare-coverage-database/view/ncd.aspx?ncdid=315&ncdver=1 (infrared and near-infrared light and heat, including monochromatic infrared energy, non-covered for diabetic and non-diabetic peripheral sensory neuropathy, wounds and ulcers of the skin and subcutaneous tissues, including pain arising from those conditions; the determination describes an array of juxtaposed infrared diodes affixed to a flexible pad held against the skin).
7. Centers for Medicare & Medicaid Services. Decision Memo for Infrared Therapy Devices (CAG-00291N). 2006. https://www.cms.gov/medicare-coverage-database/view/ncacal-decision-memo.aspx?proposed=N&ncaid=176 (the national coverage analysis underlying NCD 270.6).

Ask the questions that force the visit to name a cause. The three that matter most are “What pattern do my symptoms follow?”, “What is this evaluation ruling in and ruling out?”, and “What would each test change about my plan?” Neuropathy is a category, not a diagnosis. So an evaluation that ends at the word “neuropathy” has not finished its job.

Peripheral neuropathy shows up in many ways. It can bring numbness, tingling, aching, burning, weakness of the limbs, hyperalgesia (extra pain), allodynia (pain from light touch) and pain, in varying degrees.¹ That range is exactly why the symptom label alone cannot guide treatment. It is also why the questions below are built around finding the driver instead.

It is worth asking, because a careful workup finds an underlying cause in roughly 50 to 75 percent of patients with peripheral neuropathy.² The rest of this checklist is what “careful” looks like from the patient’s side of the table.

What symptoms should I describe to my doctor?

Where symptoms started, how they spread, and whether both sides match are the first clues a clinician works from. Your job is to describe that pattern exactly. Do not boil it down to “my feet hurt.”

Questions that establish the pattern

• Where did this start, and in what order did it spread?
• Is it burning, numbness, weakness, or a combination?
• Are both sides affected equally, or is one side worse?
• What makes it worse and what makes it better across a normal day?
• Do I have balance changes, falls, or a change in how I walk?

A pattern that starts in both feet and creeps upward points one way. A sudden, one-sided, or fast-moving pattern points another. Say which of those describes you, and say it early in the visit.

Questions that make the evaluation commit

• What category are you most concerned about today?
• What finding would change your mind about that?
• What is this evaluation trying to rule in, and what is it trying to rule out?
• If this is small fiber involvement, how would you confirm it?

Want to learn more about nerve pain and the treatments we use? Get our neuropathy video series by email.

How is diabetic neuropathy diagnosed?

Having diabetes does not settle the question. It raises a second one: is diabetes the whole driver, or one of several stacked on top of each other?

Peripheral neuropathy is mainly diagnosed in the exam room. It rests on your history and a neurological exam. Small fiber feeling is tested with temperature or pinprick. Large fiber feeling is tested with vibration. Ulcer risk is tested with 10 g monofilament pressure.¹ Nerve conduction studies and intraepidermal nerve fiber density testing are called for when features are atypical. Examples are fast symptom onset, severe neuromotor impairment, or abnormal feeling that is worse on one side.¹

Questions about testing purpose

• Does anything about my case count as atypical (unusual)?
• When would electrodiagnostic testing change what we do, rather than just confirm what we already suspect?
• If my nerve study is normal but my symptoms persist, what does that mean for the next step?
• How do my glucose history, A1c trend and kidney function change your concerns?

Regenerve performs electrodiagnostic testing (EMG/NCS) on site. That means the result is read against your history in the same building. It is not mailed back weeks later as a number without a plan.

What else causes neuropathy besides diabetes?

Nutritional, autoimmune, toxic and structural drivers can sit alongside a metabolic one, and they often do. If you have ever been told “nothing else explains it,” ask what exactly was checked. That is the useful follow-up.

Hidden-driver questions

• Besides diabetes, what other drivers are you looking at today?
• Could nutrient absorption be contributing, and how would you test that?
• Could a medicine, your drinking history, or something you were exposed to at work be involved?
• Did this begin after chemotherapy, surgery, or a shingles episode?
• If serum B12 is reported as normal, does that fully exclude a B12-related driver?

Our longer discussion of the drivers that get missed is in the hidden drivers of peripheral neuropathy. It is a fair list to bring with you to any evaluation, here or elsewhere.

What should I bring to a neuropathy appointment?

The best questions come out of your own timeline. A clinician can map the mechanism far faster when the details are on paper. Otherwise they get pieced together from memory in a fifteen-minute visit.

What to write down before you go

• The month and year symptoms began, and anything that happened around that time.
• Every prescription, store-bought medicine and supplement, with doses.
• Past surgeries, especially belly or weight-loss (bariatric) surgery.
• Alcohol history, stated honestly, because it changes the list of possible causes.
• Any prior nerve testing, lab work, or imaging, with the actual reports if you have them.

Ask what each treatment is aimed at

Once a driver is named, the questions shift from diagnosis to mechanism. The single most useful question about any proposed treatment is what it is meant to change. Is it the symptom, or the process producing the symptom?

Treatment questions worth asking

• What is the dominant driver in my case, and what does that imply for treatment?
• What is each proposed therapy targeting, and how will we know whether it worked?
• Which parts of this plan address the ongoing injury rather than the pain signal?
• How will the plan change if the driver map changes?

Regenerve offers class 4 photobiomodulation, class 3B cold laser and whole-body infrared. It also offers metabolic and nutritional care. Orthobiologic injections (PRP and BMAC) are offered too. Whatever is proposed, ask what it is aimed at before you agree to anything.

If shingles is in your history, ask about Qutenza specifically

Qutenza (capsaicin 8% patch) is FDA-approved in adults for neuropathic pain associated with postherpetic neuralgia and for neuropathic pain associated with diabetic peripheral neuropathy of the feet.³

Questions about the patch

• Does my diagnosis fall inside the approved indication?
• How long is the application, and how long is the visit?
• How often can it be repeated?
• What monitoring happens during and after the application?

It is applied in clinic by a clinician, never dispensed for home use, and repeated no more often than every three months.³

Questions that test the quality of the evaluation itself

The last set is about the clinic, not your nerves. A good evaluation should be able to answer these without pausing.

• How do you document which driver you believe is dominant, and what evidence supports it?
• What testing do you perform on site, and what gets sent out?
• When is the next touchpoint, and what should I bring to it?
• What would make you tell me this is not the right clinic for my problem?

Being evaluated in St. Louis

Regenerve is at 4477 Woodson Rd #104, St. Louis, MO 63134, minutes from St. Louis Lambert International Airport, and is led by Dr. Gurpreet Singh Padda, MD, MBA, MHP. The practice serves the St. Louis region, Missouri and Illinois.

Call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com. Office hours are Monday through Thursday 9 a.m. to 4 p.m. and Friday 9 a.m. to 1:30 p.m.

Want your answers organized before the visit? The Nerve Damage Score is a free five-question assessment. It produces a large-print report you can hand to any physician.

Frequently asked questions

What should I ask if my main symptom is numbness rather than pain?

Ask which fiber types the numbness pattern points to, and what test would confirm it. Then ask what loss of protective feeling means for foot care in the meantime. Numbness without pain still needs a driver named. See small fiber neuropathy symptoms and testing.

How do I prepare if my feet burn at night?

Write down when the burning starts, whether both sides match, and what changes it. Then ask which mechanism the clinician thinks is causing it. Bring that description, not a one-word summary. See burning feet and nerve pain.

Is a nerve conduction study always necessary?

No. Peripheral neuropathy is mainly a clinical diagnosis, made in the exam room. Nerve conduction studies are called for when features are atypical. Examples are fast onset, severe neuromotor impairment, or sensory findings that differ between sides. Ask what the result would change before you agree to it. See how to choose a neuropathy specialist.

What should I ask if I think a B12 problem was missed?

Ask how functional B12 status is checked when the blood level reads normal, and what would be measured alongside it. Then ask what treatment decision that testing would drive. See functional B12 deficiency and neuropathy.

What if gluten or celiac disease is a possibility for me?

Ask whether a gluten-related driver is on your list of possible causes. Ask what testing supports or rules it out. And ask what happens if celiac testing is negative but symptoms fit. See the gluten and neuropathy connection.

What tests confirm neuropathy?

Most peripheral neuropathy is diagnosed in the exam room, from your history and a neurological exam. Temperature or pinprick tests small fibers. Vibration tests large fibers. A 10 g monofilament checks ulcer risk. Nerve conduction studies and skin biopsy nerve fiber counts are added when features are atypical. Examples are fast onset, severe weakness or uneven feeling between sides. Regenerve performs EMG/NCS on site.

Can doctors find the cause of neuropathy?

Often, yes. A careful workup finds an underlying cause in roughly 50 to 75 percent of patients with peripheral neuropathy. That is why an evaluation that ends at the word “neuropathy” is not finished. Ask what the visit is ruling in and ruling out. Ask what finding would change the clinician’s mind.

What symptoms does peripheral neuropathy cause?

Numbness, tingling, aching, burning, weakness in the arms or legs, and pain. That includes extra sensitivity to pain (hyperalgesia) and pain from a touch that should not hurt (allodynia). The same symptoms come from many causes, so the list alone cannot guide treatment. The pattern matters more: where it started, how it spread, and whether both sides are affected equally.

Sources

1. Bodman MA, Dreyer MA, Varacallo MA. Diabetic Peripheral Neuropathy. StatPearls. StatPearls Publishing. 2024. NCBI Bookshelf NBK442009
2. Peripheral Neuropathy: Asking the Right Questions. Practical Neurology. March–April 2009. practicalneurology.com
3. Averitas Pharma, Inc. QUTENZA (capsaicin) topical system — full prescribing information. Updated July 2026. DailyMed

Get numbness in your feet checked promptly in these cases: it comes on suddenly, it is much worse on one side, it comes with real weakness, there are autonomic changes such as lightheadedness on standing, or it is getting worse over days to weeks. American Family Physician names those same features as reasons to refer a patient for electrodiagnostic studies. So does a first workup that is normal while symptoms go on.¹ Slow, even numbness in both feet is less urgent. But it still deserves a workup, because it is usually pointing to a cause somewhere else in the body.

What to notice before your visit

• Numbness that is spreading or getting worse. A changing pattern suggests the cause is still active.
• Numbness plus weakness or autonomic changes. These are the features that move a workup up the line.
• A diabetes or prediabetes history. Peripheral neuropathy affects 25% to 50% of patients with diabetes. It depends on age, years with diabetes, and control.¹
• Known abnormal labs. B12, thyroid, and metabolic results shape which cause is most likely.
• Burning, heat, and night symptoms. Small-fiber patterns can be intense while standard testing looks normal.
• Balance changes. Dulled protective feeling makes missteps more likely.

When should you worry about numbness in your feet?

Numbness means nerve signals are impaired. When it gets worse, it stops being only a feeling problem and becomes a safety problem. Walking, heat sensitivity, and balance all depend on that feedback.

Worrisome patterns that support earlier evaluation

American Family Physician advises referral for electrodiagnostic studies when symptoms are worrying. Its examples are sudden onset, a lopsided pattern, mostly motor or autonomic symptoms, and a fast-worsening course. It also advises referral when the first workup is normal and symptoms go on.¹

• Sudden or fast-developing numbness
• Clearly lopsided, much more on one side than the other
• Prominent weakness rather than numbness alone
• Autonomic signs such as lightheadedness on standing or changed sweating
• Getting worse over days to weeks

Is numbness in the feet without pain still serious?

A survey of 5,682 Japanese people, published in 2023, looked at numbness that comes without pain. Using the EQ-5D-3L, it found that quality of life fell as numbness got stronger.² Notably, in that survey, numbness of the feet and numbness in younger people were less likely to affect quality of life than numbness elsewhere.

That detail is worth saying plainly. No pain, and even a small effect on quality of life, is not proof that the nerve is unhurt. It only means the symptom is quiet.

How common is peripheral neuropathy?

American Family Physician reports that peripheral neuropathy affects 1% to 7% of the general population, with higher rates among those older than 50 years.¹ The range is wide, but the direction is steady: age raises the risk.

What if no cause is found for the numbness?

The same source notes that peripheral neuropathy is idiopathic in 25% to 46% of cases, and that this becomes more common with age.¹ A clear explanation may not show up at the first visit. That is what makes a structured workup worth the effort, not a formality.

The diabetes context

Peripheral neuropathy affects 25% to 50% of patients with diabetes, depending on age, number of years with diabetes, and level of control.¹ If diabetes is part of your history, numbness in the feet calls for a plan, not watching and waiting, because metabolic causes tend to get worse quietly.

What we are actually mapping

Neuropathy is a category, not a diagnosis. The cause decides the direction of treatment. So the workup is built to name it, not to confirm a label. Several of the causes that get missed on a first pass are covered in our review of the hidden drivers behind peripheral neuropathy.

The questions that organize the map

• Does the pattern start in the toes and move up, hitting the longest nerves first?
• Are the symptoms mostly added feelings, such as burning and tingling, or mostly lost feeling?
• Does the picture fit small-fiber damage, with burning and changed temperature feeling?
• Is there metabolic risk that points to a diabetic or prediabetic cause?
• Is there a nutrition, medicine, or toxic exposure history that points somewhere else?

What tests are done for numbness in the feet?

A workup is about making decisions. We want to know which nerves are involved, what is damaging them, and whether the cause looks metabolic, nutritional, toxic, autoimmune, or structural.

Initial laboratory evaluation

American Family Physician describes first tests that include a complete blood count, a comprehensive metabolic profile, and fasting blood glucose, thyroid-stimulating hormone, and vitamin B12 levels.¹ We read those results alongside the symptom pattern, never on their own.

Electrodiagnostic testing: what it can and cannot do

Electrodiagnostic studies measure how well the larger nerve fibers carry signals. They do not replace reading the symptom pattern, and they cannot see the smallest fibers. But they can tell a normal-looking report apart from a measurable signal failure. We do electrodiagnostic testing (EMG/NCS) on site at Regenerve.

Why burning feet at night can still matter when testing looks normal

In metabolic neuropathy, small-fiber symptoms often come first, including burning and changed temperature feeling. That is the case people find most confusing, because the report can look normal while the feeling is severe.

VNG balance testing when numbness comes with dizziness

VNG (videonystagmography) is a test of inner-ear balance, not a treatment. When numbness comes with dizziness or unsteadiness, it helps separate an inner-ear cause from a nerve cause, so the plan targets the right system.

Why cause-first planning changes what you do next

The feet report first, because the longest nerves carry the heaviest load and depend on the longest supply route for oxygen and nutrients. When that supply weakens, those fibers misfire first.

Diabetic peripheral neuropathy behaves as a tiny-vessel and metabolic problem that happens to show up in the feet. That is why treatment aimed only at the feeling tends to leave the cause untouched.

What is offered here, described accurately

Class 4 photobiomodulation, class 3B cold laser, and whole-body infrared are offered in clinic alongside metabolic and nutrition care, guided by what the workup finds. Orthobiologic injections (PRP and BMAC) are offered as well. We do not promise nerve regeneration, reversal, or a cure. We publish no success rate for any of it.

What you can do before your visit

• Check your feet daily with a mirror if protective feeling is dulled, so skin breakdown is found early.
• Write down the timing and how it is changing, including whether burning is worse at night and whether symptoms are spreading.
• Note exposures, medicines, and metabolic history, including diabetes status, nutrition, and any chemotherapy.

Where we are and how to start

Regenerve is located at 4477 Woodson Rd #104, St. Louis, MO 63134, minutes from St. Louis Lambert International Airport, and we see patients from across the St. Louis region, Missouri and Illinois. You can call (314) 886-5739 or text (314) 886-5902, or email info@regenerve.com.

The free Nerve Damage Score is a five-question starting point. It sorts out the cause question before your visit. If your numbness is new, getting worse, or paired with any of the red flags above, do not wait on it.

Frequently asked questions

How do I know whether numbness in my feet is urgent?

Treat it as urgent in these cases: the onset is sudden, the numbness is clearly worse on one side, there is real weakness and not only numbness, there are autonomic signs such as lightheadedness on standing, or the change is getting worse over days to weeks. American Family Physician lists exactly those features as reasons to refer for electrodiagnostic studies.¹ See the symptom patterns we look for in the feet.

Do I need an EMG or nerve conduction study if I only have numbness?

Not always. Electrodiagnostic testing earns its place when the symptoms are worrying, or when the first workup is normal and the symptoms go on. We do that testing on site here, so the question is whether the result will change the plan. See which specialist to see when neuropathy has not improved.

What laboratory tests are usually part of the first workup?

American Family Physician describes first tests that include a complete blood count, a comprehensive metabolic profile, and fasting blood glucose, thyroid-stimulating hormone, and vitamin B12 levels.¹ Those results point to a metabolic, nutrition, or thyroid cause, instead of just confirming a label. See why a “normal” B12 result can still be misleading.

Can burning feet at night be small fiber neuropathy?

It can. Burning and changed temperature feeling often show up early in metabolic neuropathy. Standard nerve conduction studies can look normal while symptoms are intense, because those studies do not measure the smallest fibers. See small fiber neuropathy symptoms and testing.

Where does Qutenza fit into treating numb or burning feet?

Qutenza (capsaicin 8% patch) is FDA-approved in adults only for neuropathic pain from postherpetic neuralgia and from diabetic peripheral neuropathy of the feet. It is applied in clinic by a clinician, never dispensed for home use, and repeated no more often than every three months. See how Qutenza is used in clinic.

How long is too long for your feet to be numb?

Do not wait it out. Numbness that is new, getting worse, or worsening over days to weeks should be checked promptly. So should numbness that is sudden, one-sided or paired with weakness. Slow numbness in both feet is less urgent. But it still deserves a workup, because it is usually pointing to a cause somewhere else in the body.

Is numbness in the feet dangerous?

It can be. Walking, heat sensitivity and balance all depend on feedback from your feet. So numbness becomes a safety problem, not just an odd feeling. Missteps get more likely, and a blister or burn can go unnoticed until the skin breaks down. If protective feeling is dulled, check your feet daily with a mirror so problems are found early.

What can a doctor do for numb feet?

The first job is naming the cause: metabolic, nutritional, toxic, autoimmune or structural. That starts with labs such as a blood count, metabolic profile, fasting glucose, thyroid and B12. On-site EMG/NCS is added when it will change the plan. At Regenerve, class 4 photobiomodulation, class 3B cold laser, whole-body infrared, metabolic and nutrition care and PRP or BMAC injections are then guided by what the workup finds.

Sources

1. Castelli G, Desai KM, Cantone RE. Peripheral Neuropathy: Evaluation and Differential Diagnosis. American Family Physician. 2020;102(12):732-739. https://www.aafp.org/pubs/afp/issues/2020/1215/p732.html (general-population prevalence of 1% to 7%; idiopathic in 25% to 46% of cases; 25% to 50% of patients with diabetes; initial laboratory evaluation; criteria for electrodiagnostic referral).
2. Nagai S, Niwa H, Terajima Y, et al. The Relationship between Numbness and Quality of Life. Journal of Clinical Medicine. 2023;12(4):1324. https://doi.org/10.3390/jcm12041324 (epidemiological survey of 5,682 Japanese respondents; quality of life declined as the intensity of numbness without pain increased, with foot numbness and numbness in younger respondents less likely to affect quality of life).