Overview
Your doctor may use several different approaches to figure out if you
have SFN. This usually includes talking about your symptoms, doing a
physical exam, and getting a skin punch biopsy. The process might seem slow,
but each step helps build a clear picture of what's happening with your nerves.
The good news is that doctors are getting better at recognizing and
diagnosing SFN. New testing methods
have made it easier to confirm the diagnosis. Getting the right diagnosis
is worth the wait because it opens the door to treatments that can help
you feel better.
Medical History and Physical Exam
Your diagnosis journey starts with telling your doctor about your
symptoms. This conversation is very important because SFN symptoms can
be different from person to person. Your doctor needs to understand exactly
what you're feeling and when it started.
During your appointment, your doctor will ask detailed questions about
your pain and other symptoms.
They'll want to know where you feel pain, what it feels like, when it
happens, and what makes it better or worse. Be as specific as possible
about your symptoms.
- When did your symptoms start? - Try to remember if they began gradually or suddenly.
- Where do you feel symptoms? - Usually starting in feet and hands, sometimes spreading upward.
- What does the pain feel like? - Burning, stabbing, tingling, numbness, or sensitivity to touch.
- What makes it worse? - Heat, cold, stress, activity, or time of day.
- What helps? - Rest, medication, temperature changes, or other treatments you've tried.
- Family history - Whether anyone in your family has had similar problems.
- Medical conditions - Diabetes, autoimmune diseases, vitamin deficiencies, or other health problems.
- Medications - All prescription drugs, over-the-counter medicines, and supplements you take.
The physical exam helps your doctor look for signs of nerve damage.
They'll test your reflexes, check how well you can feel light touch and
vibration, and look at your skin for any changes. They might also check
your blood pressure and heart rate.
Your doctor will also want to know about other health conditions that
can cause neuropathy. Diabetes is the most common cause,
but autoimmune diseases, vitamin deficiencies, and certain medications
can also damage small nerve fibers.
Diagnostic Tests
The most definitive test for SFN is a skin biopsy.
This involves taking tiny samples of skin to count the small nerve fibers.
It might sound scary, but it's a simple procedure that's usually done in
the doctor's office with local numbing medicine.
- Skin biopsy - Small skin samples are taken from your leg and sometimes your arm. The samples are examined under a microscope to count nerve fibers.
- Quantitative sensory testing (QST) - Tests how well you can feel different temperatures, vibrations, and pressure.
- Sudomotor testing - Checks how well your sweat glands work by measuring your body's response to mild electrical stimulation.
- Blood tests - Look for diabetes, vitamin deficiencies, autoimmune diseases, and other conditions that can cause neuropathy.
- Nerve conduction studies - While these don't detect small fiber damage, they can rule out problems with larger nerves.
- Autonomic function tests - Check if your automatic body functions like heart rate and blood pressure are affected.
The skin biopsy is considered the gold standard for diagnosing SFN.
During this test, your doctor takes a small circular piece of skin, usually
from your lower leg. The sample is sent to a lab where specialists count
the small nerve fibers and compare them to normal levels.
Blood tests are important to find out what might be causing your neuropathy.
Your doctor will usually check for diabetes and prediabetes,
vitamin B12 levels, thyroid function, and signs of autoimmune diseases.
Finding and treating the underlying cause can sometimes slow down or even
improve neuropathy symptoms.
Some tests might need to be repeated over time to see how your condition
is changing. This helps your doctor understand whether your neuropathy
is getting worse, staying the same, or improving with treatment.
Working with Specialists
Many people with SFN work with neurologists, doctors who specialize
in conditions affecting the nervous system. Neurologists have special
training in diagnosing and treating different types of neuropathy, including SFN.
Your family doctor might refer you to a neurologist if they suspect
you have SFN. Some neurologists have even more specialized training in
peripheral neuropathy,
which means they focus specifically on nerve problems like SFN.
Depending on what might be causing your neuropathy, you might also
work with other specialists. If you have diabetes, an endocrinologist
can help manage your blood sugar. If autoimmune disease is suspected,
a rheumatologist might get involved.
- Neurologist - Specializes in diagnosing and treating nerve disorders. They can perform nerve tests and manage neuropathy medications.
- Endocrinologist - Helps manage diabetes and other hormone-related conditions that can cause neuropathy.
- Rheumatologist - Treats autoimmune diseases that might be causing nerve damage.
- Pain management specialist - Focuses on different ways to control chronic pain from neuropathy.
- Physical therapist - Helps you stay active and teaches exercises that can reduce pain and improve function.
When you see a specialist, bring a list of all your symptoms, medications,
and any test results you already have. Don't be afraid to ask questions
about your condition and treatment options. Good specialists want to work
with you as a team to manage your neuropathy.
Sometimes you might need to see more than one specialist to get the
best care. This team approach can help address all aspects of your condition,
from finding the cause to managing symptoms and staying as active as possible.
Written by the SFN Foundation
August 20, 2025
Page References
- 1. Small Fiber Neuropathy: What It Is, Symptoms & Treatment - Cleveland Clinic
- 2. Peripheral neuropathy - Diagnosis and treatment - Mayo Clinic
- 3. Diabetic neuropathy - Symptoms and causes - Mayo Clinic
- 4. Skin biopsy for the diagnosis of small fiber neuropathy - NIH
- 5. Understanding Peripheral Neuropathy - Foundation for Peripheral Neuropathy
- 6. Prediabetes - Symptoms and causes - Mayo Clinic
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