How to Distinguish Between Small Fiber and Large Fiber Neuropathy

johnhayesjr1
Oct 6
2 min read

Not all neuropathy is the same and differentiating between small fiber and large fiber neuropathy is critical to delivering the right diagnosis and treatment. Many patients present with mixed symptoms, unclear test results, and years of frustration. As an independent physician, you have the opportunity to offer clarity without the limitations of insurance-driven protocols.

Small Fiber vs. Large Fiber: What’s the Difference?

🔹 Small Fiber Neuropathy (SFN)

Affects unmyelinated C fibers and thinly myelinated Aδ fibers
Symptoms: burning, stinging, tingling, sensitivity to temperature, electric shocks
Reflexes often remain intact
EMG/NCS usually normal
Diagnosis is primarily clinical (or by skin biopsy if needed)

🔹 Large Fiber Neuropathy

Affects myelinated sensory and motor fibers
Symptoms: numbness, vibration loss, balance issues, muscle weakness
Reflexes diminished or absent
Often shows up on EMG/NCS

Understanding the fiber type involved helps explain why symptoms don’t match standard tests and why many patients have been told "nothing is wrong."

How This Transforms Your Practice

As a direct-pay physician, you can integrate a more functional, nuanced workup for neuropathy:

Ask the right questions: “Do hot or cold surfaces feel painful or strange?”
Use simple, in-office tools: tuning fork (128 Hz), pinprick, temperature, Romberg
Test B12, B6, fasting insulin, CRP, ANA, and screen for gluten sensitivity or autoimmune markers
Document symptom patterns in diagrams or digital charts to track progression or improvement

Patients want to understand their pain. When you offer a precise explanation, you gain trust and referrals.

Treat the Right Type, Get Better Results

Neuropathy treatment isn’t one-size-fits-all. Red light therapy, targeted nutrients, and regenerative protocols may benefit both types, but clinical strategy differs based on fiber involvement. Getting it right sets you apart.

Want to Master the Art of Neuropathy Differentiation?

Chat with John Hayes Jr., MD to learn how to use tools help you distinguish, document, and treat nerve dysfunction with greater precision—and deliver results that system-based clinics can’t touch.