Educational information, not a treatment plan. This overview is meant to help you understand the condition and prepare informed questions. Diagnosis and treatment decisions should always be made with a qualified healthcare professional. Find a specialist or read our medical disclaimer.
Damage to the small nerve fibers that transmit pain and temperature sensations, causing burning pain, tingling, and numbness.
Overview
Small Fiber Neuropathy (SFN) is a condition that affects the small, unmyelinated nerve fibers in the skin and organs. These nerves are responsible for transmitting pain and temperature sensations and controlling autonomic functions like heart rate and digestion. When these fibers are damaged, patients experience burning pain, tingling, numbness — typically starting in the feet and hands. SFN can also cause autonomic symptoms, including heart rate and blood pressure irregularities, digestive issues, and sweating abnormalities. SFN often co-occurs with other conditions like fibromyalgia, POTS, and EDS. It can be caused by diabetes, autoimmune conditions, or may be idiopathic (no identified cause).
Common Symptoms
Symptoms include: • Burning, tingling, or shooting pain in the feet and hands • Numbness or altered sensation • Allodynia (pain from light touch) • Temperature dysregulation (feeling too hot or cold) • Autonomic symptoms (dizziness, rapid heart rate, digestive issues) • Dry eyes and mouth • Skin color changes or swelling Symptoms often worsen at night and may be triggered by heat or activity.
Diagnosis
Diagnosis involves: • Detailed medical history and symptom assessment • Neurological exam • Skin biopsy — the gold standard, measuring nerve fiber density in the skin • QSART (Quantitative Sudomotor Axon Reflex Test) for autonomic function • Nerve conduction studies (to rule out large fiber neuropathy) • Blood tests to identify potential causes Skin biopsy is key, as standard nerve conduction tests don't detect small fiber damage.
Current Treatments
Treatment focuses on symptom management and addressing underlying causes: • Medications for nerve pain (gabapentin, pregabalin, duloxetine) • Treating underlying conditions (diabetes, autoimmune disease) • Intravenous immunoglobulin (IVIG) for autoimmune SFN • Physical activity and lifestyle modifications • Pain psychology and coping strategies • Treatment of co-occurring conditions (POTS, digestive issues) Treatment is highly individualized based on the underlying cause.
Research Summary
SFN research is expanding, particularly its connection to dysautonomia and connective tissue disorders. Studies are exploring autoimmune mechanisms, genetic causes, and new treatment approaches. More research is needed on SFN in patients without identified causes (idiopathic SFN).
Community Resources
SFN is often invisible and misunderstood. Connecting with others who understand burning nerve pain and autonomic symptoms can provide validation and practical support. Explore our Stories page and community resources.
References
This overview is based on published clinical literature on small fiber neuropathy. Content is reviewed regularly. This information is for educational purposes only and should not replace professional medical advice.