Hello @cwallen9, welcome to Connect. I was diagnosed with idiopathic small fiber peripheral neuropathy but only through an EMG and I believe the skin biopsy is the more definitive test used. I have no medical training or background but I'm like you in that I like to know what results mean and why. I did find a few references that may help clear it up for you.

The Value of Including Sweat Gland Nerve Fiber Density (SGNFD) Analysis in the Neuropathy Work-up (P6.088)
-- http://n.neurology.org/content/82/10_Supplement/P6.088

Diagnostic Utility of Sweat Gland Nerve Fiber Density in Small Fiber Neuropathy (P2.111)
-- http://n.neurology.org/content/90/15_Supplement/P2.111

Epidermal Nerve Fiber Density - Normative Reference Range and Diagnostic Efficiency
-- https://jamanetwork.com/journals/jamaneurology/fullarticle/774528

Are you able to ask your neurologist what the low sweat gland density numbers mean in layman's terms? Sometimes it may be the easiest answer.

John