Nerve Symptoms & hEDS/HSD
Burning, Numb, or Tingling Skin That Isn't a Pinched Nerve: Small Fiber Neuropathy in Hypermobility
None of us writing this are doctors. This page collects what the published research actually says about small fiber neuropathy in hEDS/HSD, so you have something concrete to bring to a doctor.
If you've had burning, prickling, or numb sensations in your hands, feet, or more widely across your skin, and a nerve conduction study came back normal, that doesn't mean nothing is wrong. Standard nerve conduction studies only measure large nerve fibers. There's a separate, smaller class of nerve fiber that a different test is needed to check, and it's now been studied directly in hEDS.
How Common Is Small Fiber Neuropathy in hEDS?
A 2023 study published in the European Journal of Neurology (Igharo et al.) compared 31 people with hEDS to 31 matched healthy controls using skin biopsy, the standard way to directly count small nerve fiber density in the skin, along with quantitative sensory testing and tilt-table testing. Nineteen of the 31 hEDS patients, 61%, met diagnostic criteria for small fiber neuropathy (SFN) based on reduced intraepidermal nerve fiber density on biopsy. The nerve fiber loss wasn't confined to the feet, where SFN is most commonly checked for: 89% of the hEDS patients had reduced nerve fiber density at the thigh as well as the lower leg, a generalized rather than purely length-dependent pattern.
A separate 2022 study in the Journal of Internal Medicine (Fernandez et al.), using a larger cohort of 79 people with hEDS or HSD, found small nerve fiber dysfunction on quantitative sensory testing in 70% of patients (55 of 79) and a structural deficit on skin biopsy in 78% of those tested (54 of 69). Two different research groups, two different testing approaches, and both landed on the same conclusion: measurable small fiber damage is common in this population, not a rare finding.
Why This Might Explain Symptoms Beyond Numbness and Burning
Small nerve fibers don't just carry pain and temperature sensation. They also regulate sweating, blood vessel constriction, and other autonomic functions. In the Igharo study, 10 of the 19 hEDS patients with confirmed SFN, 32%, also met criteria for POTS. That overlap is a plausible mechanical link, not a coincidence: damaged small fibers are part of the same system that keeps blood vessels and heart rate properly regulated when you stand up, which is exactly what goes wrong in POTS.
Neither study claims small fiber neuropathy explains every symptom in hEDS, and both are working with moderate sample sizes that need replication in larger, more diverse cohorts before the exact prevalence figures should be treated as settled. What they do establish is that burning, numb, or tingling sensations in hEDS/HSD have a documented, biopsy-confirmed physical explanation in a meaningful share of patients, not just something to be written off as anxiety or unexplained.
Read more on the hub page
Chronic Widespread Pain and Central Sensitization in Hypermobility
What to do about it
If you have burning, prickling, numb, or otherwise abnormal skin sensations, especially if a standard nerve conduction study came back normal, it's worth asking a neurologist specifically about small fiber neuropathy testing. A skin punch biopsy to measure intraepidermal nerve fiber density is the diagnostic standard used in both studies above, and quantitative sensory testing is a non-invasive complementary option some clinics offer.
If you already have a POTS diagnosis alongside unexplained numbness or burning, mentioning the SFN-POTS overlap found in this research is a reasonable way to ask whether the two might be connected rather than being treated as two unrelated problems.
Sources referenced on this page
- 01Igharo et al., 'Skin biopsy reveals generalized small fibre neuropathy in hypermobile Ehlers-Danlos syndromes,' European Journal of Neurology, 2023 (n=31 vs. 31 controls)
- 02Fernandez et al., 'Small fiber neuropathy in hypermobile Ehlers Danlos syndrome/hypermobility spectrum disorder,' Journal of Internal Medicine, 2022;292(6):957-960 (n=79)