What Is Small Fiber Neuropathy?

Not Sure Where to Start?

Choose the description that sounds most like what you’re experiencing:

🔥 My feet burn → Why Do My Feet Burn at Night?

🧊 My feet feel cold even when they’re warm → Why Are My Feet Cold Even When They Feel Warm?

⚡ My feet tingle or sting → Is Tingling in My Feet Always a Sign of Peripheral Neuropathy?

👣 My feet are numb → What Causes Numbness in My Toes?

🔍 My EMG was normal, but I still have symptoms → You’re in the right place. Keep reading.

What You’ll Learn

In this chapter you’ll discover:

• What small nerve fibers do
• How small fiber neuropathy differs from other types of neuropathy
• Why burning, stinging, and temperature changes may occur
• Why routine nerve conduction studies can be normal
• What tests may help support a diagnosis
• What medical conditions may contribute
• Why identifying the underlying cause matters
• What realistic treatment and management goals may look like

Quick Answer

Small fiber neuropathy is a condition involving damage or dysfunction of the small nerve fibers that help transmit pain, temperature, and certain automatic body functions.

These fibers are different from the larger nerve fibers that help control muscles, detect vibration, and provide information about body position.

When small fibers are affected, patients may experience:

• Burning pain
• Stinging
• Pins and needles
• Electric sensations
• Unusual sensitivity to touch
• Altered temperature sensation
• Pain from normally nonpainful contact

Some people also experience symptoms involving automatic body functions, such as sweating, digestion, or blood pressure regulation.

One of the most confusing aspects is that routine EMG and nerve conduction studies may be normal in someone with small fiber neuropathy.

That does not mean every person with burning feet has small fiber neuropathy.

It means the type of nerve being evaluated matters.

Your Peripheral Nerves Are Not All the Same

I often explain peripheral nerves to patients as a communication system.

Different nerve fibers carry different types of information.

Some tell your brain:

“Your foot is touching the floor.”

Others tell it:

“That surface is hot.”

Others help your muscles move.

And still others help regulate automatic functions you rarely think about.

Understanding these differences helps explain why neuropathy can produce such a wide variety of symptoms.

What Do Small Nerve Fibers Do?

Small nerve fibers are involved primarily in transmitting information related to:

• Pain
• Temperature
• Certain types of touch
• Autonomic functions

Autonomic functions are the automatic processes your body regulates without conscious effort.

These include aspects of:

• Sweating
• Blood pressure regulation
• Heart rate
• Digestion
• Bladder function

Not every patient with small fiber neuropathy develops autonomic symptoms.

But when they occur, they may provide important clues.

How Is Small Fiber Neuropathy Different From Large-Fiber Neuropathy?

Large nerve fibers are important for functions such as:

• Vibration sensation
• Position sense
• Reflexes
• Muscle control

When large fibers are affected, patients may develop problems involving balance, reduced reflexes, weakness, or difficulty sensing where their feet are positioned.

Small fiber neuropathy more commonly produces symptoms involving pain and temperature.

That is why someone may say:

“My feet burn terribly, but I can still feel vibration.”

Or:

“My feet hurt when the bedsheet touches them, but my strength seems normal.”

Those patterns can be consistent with small fiber involvement.

However, some patients have both small- and large-fiber involvement, and symptoms can overlap.

Why Does Small Fiber Neuropathy Cause Burning Feet?

Small nerve fibers help transmit pain and temperature signals.

When those fibers become damaged or dysfunctional, the nervous system may receive abnormal signals.

A patient may experience burning even though there is no external heat source.

They may feel stinging even though nothing is touching the skin.

They may experience electric sensations without an electrical injury.

The sensation is real.

The problem is that the nerve signaling is abnormal.

Why Are Symptoms Often Worse at Night?

Many patients notice burning or stinging more intensely when they lie down to sleep.

There may be several contributing factors.

During the day, your brain is occupied with:

• Walking
• Working
• Conversations
• Television
• Driving
• Other activities

At night, those distractions disappear.

The nervous system may become more aware of sensations that were present throughout the day.

Temperature changes, fatigue, and sleep disruption may also influence symptom perception.

Nighttime symptoms do not automatically mean the neuropathy is progressing.

But persistent or worsening symptoms deserve evaluation.

What Is Allodynia?

One symptom that can occur with small fiber neuropathy is called allodynia.

Allodynia means pain caused by something that would not normally be painful.

For example:

• A bedsheet touching the feet
• Light pressure from socks
• Gentle contact with the skin
• A mild temperature change

A patient may say:

“Doctor, even the sheets hurt my feet.”

That description can be an important clue.

Can Small Fiber Neuropathy Cause Numbness?

Yes, although burning and painful sensations are often emphasized.

Some patients experience reduced ability to detect:

• Pinprick
• Temperature
• Certain types of touch

Others may describe a combination of burning and numbness.

That may sound contradictory, but it is possible for damaged nerves to produce both abnormal sensations and reduced sensation.

Can Small Fiber Neuropathy Affect More Than the Feet?

Yes.

Many cases follow a length-dependent pattern, meaning symptoms begin in the toes or feet and may gradually move upward.

However, some forms may affect other areas in a less typical pattern.

Symptoms can sometimes involve:

• Hands
• Arms
• Trunk
• Face
• Other regions

A non-length-dependent pattern may lead clinicians to consider different possible causes and additional evaluation.

The distribution of symptoms matters.

What About Autonomic Symptoms?

Small nerve fibers also participate in autonomic regulation.

Depending on the condition, some patients may experience symptoms such as:

• Abnormal sweating
• Dizziness when standing
• Changes in heart rate
• Digestive disturbances
• Bladder symptoms
• Abnormal temperature regulation

These symptoms are not specific to small fiber neuropathy and can have many other causes.

But when they occur alongside burning or temperature-related nerve symptoms, they may deserve further investigation.

Why Can My EMG Be Normal?

This is one of the most important questions in this chapter.

Routine nerve conduction studies and needle EMG primarily evaluate larger nerve fibers and muscle-related electrical activity.

Small nerve fibers are not adequately assessed by standard nerve conduction studies.

Therefore, someone with predominantly small fiber neuropathy may have normal routine electrodiagnostic results.

That does not mean the test was useless.

It may help rule out or identify other types of nerve involvement.

But it does mean that a normal result cannot, by itself, exclude small fiber neuropathy.

How Is Small Fiber Neuropathy Diagnosed?

Diagnosis begins with the patient’s history and examination.

A healthcare professional may consider:

• The pattern of symptoms
• Burning or stinging sensations
• Temperature changes
• Sensitivity to touch
• Sensory examination findings
• Medical history
• Medication history
• Laboratory results
• Other neurological findings

When appropriate, specialized testing may be recommended.

What Is a Skin Biopsy?

A skin biopsy is one method used to evaluate suspected small fiber neuropathy.

A small sample of skin is removed and examined to assess the density of small nerve fibers.

Reduced intraepidermal nerve fiber density can provide objective evidence supporting small fiber neuropathy.

The procedure is generally performed using local anesthesia.

Skin biopsy is not necessary for every patient, and results must be interpreted in the context of the clinical picture.

Are There Other Specialized Tests?

Depending on the symptoms and clinical setting, specialists may consider additional testing of small-fiber or autonomic function.

Examples may include:

• Quantitative sensory testing
• Sudomotor testing
• Autonomic reflex testing
• Other specialized neurological evaluations

These tests are not appropriate for every patient.

The goal is to select testing that helps answer the clinical question.

What Causes Small Fiber Neuropathy?

Small fiber neuropathy can be associated with a variety of medical conditions.

Potential causes or contributing factors may include:

• Diabetes
• Impaired glucose regulation
• Vitamin B12 deficiency
• Certain autoimmune disorders
• Certain infections
• Toxic exposures
• Some medications
• Hereditary conditions
• Other metabolic or systemic diseases

In some cases, no specific cause is identified despite appropriate evaluation.

That is called idiopathic small fiber neuropathy.

Why Blood Sugar Matters

Diabetes is a well-known cause of peripheral neuropathy.

Abnormal glucose regulation may also be associated with small fiber nerve dysfunction.

That is why evaluation of blood sugar and metabolic health may be appropriate in some patients.

However, not every person with small fiber neuropathy has diabetes.

And not every person with burning feet has small fiber neuropathy.

The diagnosis should be based on the entire clinical picture.

Why Nutrition Matters

Certain nutritional deficiencies can contribute to nerve dysfunction.

Vitamin B12 is one important example.

But supplements should be used thoughtfully.

Excessive vitamin B6 intake can itself cause neuropathy.

That is why I encourage patients to bring a complete list of medications, vitamins, and supplements to their appointments.

More is not always better.

Can Small Fiber Neuropathy Be Reversed?

The answer depends on the underlying cause and the degree of nerve injury.

Some causes may be treatable or manageable.

For example, correcting a documented deficiency or addressing a contributing medical condition may help prevent further injury and, in some cases, allow improvement.

Other forms may persist despite appropriate care.

There is no responsible way to guarantee complete reversal for every patient.

But that does not mean there are no meaningful options.

What Are the Goals of Treatment?

Treatment should be individualized.

Depending on the patient, goals may include:

• Identifying and addressing contributing factors
• Managing neuropathic pain
• Improving sleep
• Protecting the feet
• Maintaining strength and balance
• Supporting safe physical activity
• Managing associated medical conditions
• Improving quality of life

Some patients may benefit from medications specifically used for neuropathic pain.

Others may need treatment directed at an underlying medical condition.

Physical therapy, exercise, foot care, and other supportive strategies may also be appropriate.

The right plan depends on the person—not simply the diagnosis.

How We Evaluate Suspected Small Fiber Neuropathy at Advanced Integrated Medical

When a patient tells me:

“My feet burn, but my EMG was normal,”

I don’t want to dismiss the symptoms.

I also don’t want to automatically diagnose small fiber neuropathy.

Instead, I want to understand:

• Where are the symptoms?
• When did they begin?
• Are they symmetrical?
• Are they progressing?
• Is there numbness?
• Is there weakness?
• Are there balance problems?
• Are there autonomic symptoms?
• What medical conditions are present?
• What medications and supplements are being used?
• What testing has already been performed?

Depending on the findings, additional laboratory testing, neurological evaluation, or specialized testing may be appropriate.

Our goal is to understand the pattern and determine the most appropriate next step.

About Dr. Dee

Dr. D. Scott (“Dee”) Stevens has spent nearly four decades helping patients with peripheral neuropathy, chronic pain, musculoskeletal disorders, sports injuries, and regenerative medicine.

Throughout his career, he has cared for patients from all walks of life—including professional, collegiate, and Olympic athletes, professional football players, Major League Baseball players, professional boxers, and MMA fighters.

His approach emphasizes listening carefully, examining thoughtfully, and helping patients understand why their symptoms may be occurring.

Because a diagnosis is most useful when it helps guide the next decision.

Dr. Dee’s Clinical Pearl

One of the most frustrating things a patient can hear is:

“Your test is normal, so nothing is wrong.”

A normal test can be valuable information.

But it only tells us what that particular test was designed to evaluate.

If someone has persistent burning, stinging, or temperature disturbances, I believe those symptoms deserve thoughtful consideration—even when routine testing is reassuring.

The goal is not to force an abnormal diagnosis.

The goal is to understand the patient.

Dr. Dee’s Office Conversation

Patient: “Doctor, my feet burn every night, but my nerve conduction study was normal. Does that mean I’m imagining it?”

Dr. Dee: “No. A normal nerve conduction study doesn’t evaluate every type of nerve fiber. Small fiber neuropathy is one possibility, but there are others. Let’s look at your symptoms, examination, medical history, and what testing has already been done. Then we can decide whether additional evaluation makes sense.”

Facing One of the Biggest Fears

“I’m Afraid No One Will Ever Figure Out What’s Wrong.”

Living with unexplained symptoms can be exhausting.

Patients may begin to feel that they have to prove their pain is real.

They may become discouraged after normal test results.

They may wonder whether anyone believes them.

But a normal test does not erase your experience.

At the same time, good healthcare requires us to remain open-minded.

The answer may be small fiber neuropathy.

It may be another neurological condition.

It may be a different medical problem entirely.

The goal is not to choose a diagnosis that sounds convincing.

The goal is to keep asking the right questions.

Patient Success Principle #12

Understand What Your Test Actually Measures

Before assuming a test has answered everything, ask:

What was this test designed to evaluate?

What does a normal result tell us?

What does it not tell us?

Does this result fit my symptoms?

Are there other explanations we should consider?

Understanding the purpose and limitations of testing can reduce confusion and help you make better-informed decisions.

Ask Dr. Dee

“Doctor, if my EMG is normal, should I ask for a skin biopsy?”

Not automatically.

A skin biopsy may be useful in selected patients when small fiber neuropathy is suspected and confirmation would help guide diagnosis or management.

But the decision should depend on your symptoms, examination, medical history, and previous testing.

The better question is:

“Would this test help answer an important question about my condition?”

Lesson I’ve Learned in Nearly 40 Years

A Normal Test Is Not the Same as a Complete Explanation

Over the years, I’ve learned that patients sometimes become discouraged because they expect one test to explain everything.

But healthcare rarely works that way.

A test may answer one question while leaving another unanswered.

That doesn’t mean the evaluation has failed.

It means we need to understand what we’ve learned and decide what comes next.

The most useful question is often not:

“Why didn’t this test find something?”

It’s:

“What does this result tell us—and what should we investigate next?”

The Hope Principle

If you’ve been living with burning, stinging, or unexplained nerve symptoms, I want you to remember something:

Uncertainty is not the same as hopelessness.

Sometimes the next step is identifying an underlying cause.

Sometimes it’s obtaining specialized testing.

Sometimes it’s improving symptom management.

Sometimes it’s protecting your feet, sleep, strength, or daily function.

And sometimes it’s simply finding a healthcare professional who will listen carefully and help you understand the possibilities.

Hope doesn’t require a guarantee.

It requires a thoughtful plan and a willingness to keep moving forward.

“I believe the best healthcare decisions are made when patients understand their condition. My job isn’t simply to treat symptoms—it’s to help you understand why they’re happening and what your options are.”

— Dr. D. Scott (“Dee”) Stevens

Frequently Asked Questions

Is small fiber neuropathy the same as peripheral neuropathy?

Small fiber neuropathy is a type of peripheral neuropathy that primarily affects small nerve fibers involved in pain, temperature, and certain autonomic functions.

Can small fiber neuropathy cause burning feet?

Yes. Burning, stinging, electric sensations, and abnormal temperature sensations are common symptoms.

Can I have small fiber neuropathy with a normal EMG?

Yes. Routine EMG and nerve conduction studies primarily evaluate larger nerve fibers and may be normal in predominantly small fiber neuropathy.

Does a normal EMG prove I have small fiber neuropathy?

No. A normal EMG does not diagnose small fiber neuropathy. Diagnosis requires consideration of symptoms, examination, and sometimes specialized testing.

What is the most common test for small fiber neuropathy?

Skin biopsy measuring intraepidermal nerve fiber density is one commonly used objective test. Other specialized tests may be appropriate depending on the clinical situation.

Can small fiber neuropathy affect digestion or blood pressure?

It can when autonomic small nerve fibers are involved, although these symptoms have many possible causes and require appropriate evaluation.

Can small fiber neuropathy be reversed?

It depends on the cause and severity. Some underlying causes may be treatable or manageable, and some patients improve. Complete recovery cannot be guaranteed.

Is small fiber neuropathy always caused by diabetes?

No. Diabetes is one possible cause, but nutritional, autoimmune, hereditary, toxic, medication-related, and other causes may also be involved. Some cases remain idiopathic.

Key Takeaways

• Small fiber neuropathy affects small nerve fibers involved in pain, temperature, and certain autonomic functions.
• Burning, stinging, electric sensations, and unusual sensitivity are common symptoms.
• Routine EMG and nerve conduction studies may be normal.
• A normal EMG does not automatically diagnose small fiber neuropathy.
• Skin biopsy and other specialized tests may be useful in selected patients.
• Identifying the underlying cause is an important part of evaluation.
• Treatment should be individualized and based on the cause, symptoms, and functional goals.
• A normal test does not mean your symptoms aren’t real—but it also doesn’t mean we should assume the diagnosis.

Why Patients Choose Advanced Integrated Medical

At Advanced Integrated Medical, we believe patients deserve thoughtful evaluation rather than assumptions.

If your feet burn, sting, or feel unusually hot or cold, we want to understand the pattern.

If your routine testing has been normal, we want to understand what was actually evaluated.

And if additional testing or referral is appropriate, we believe that should be part of the conversation.

Our goal is not simply to give your symptoms a name.

Our goal is to help you understand what may be happening, identify contributing factors when possible, and determine the most appropriate next step.

Continue Exploring the Learning Center

You may also want to read:

• Why Do My Feet Burn at Night?
• Why Are My Feet Cold Even When They Feel Warm?
• Is Tingling in My Feet Always a Sign of Peripheral Neuropathy?
• What Tests Are Used to Diagnose Peripheral Neuropathy?
• Is Peripheral Neuropathy Always Caused by Diabetes?
• What Vitamins Are Important for Healthy Nerves?
• Can Peripheral Neuropathy Be Reversed?
• I’ve Been Diagnosed With Peripheral Neuropathy—What Should I Do Next?

Medical Disclaimer

This article is intended for educational purposes only and is not a substitute for individualized medical diagnosis, testing, or treatment.

Burning, tingling, numbness, temperature disturbances, and autonomic symptoms can have many possible causes. The appropriate evaluation and treatment depend on the individual.

Seek prompt medical evaluation for new or rapidly progressive weakness, significant changes in walking, new foot drop, fainting, severe autonomic symptoms, or other concerning neurological changes. Sudden one-sided weakness, facial drooping, speech difficulty, or other possible signs of stroke require emergency medical attention.

Ready to Learn More?

If your feet burn, sting, or feel unusually hot or cold—and especially if routine testing has not explained your symptoms—don’t assume that your questions have been answered.

Ask:

What type of nerve fibers may be involved?

What does my testing actually tell us?

What possible causes should we consider?

And what is my next best step?

At Advanced Integrated Medical, our goal is to help you understand the entire picture and make informed decisions about your care.

Because understanding your symptoms is often the first step toward finding a better path forward.