The Sudomotor or sweat motor is related to the skin microcirculation and nerve fibers controlling the activity of the sweat glands.

Sudomotor Testing is the most sensitive test to detect small fiber neuropathy. It is the only non-invasive method of detecting small fiber neuropathy. This is what makes it extremely useful to physicians. Small but small fiber peripheral neuropathy is a type of peripheral neuropathy that occurs from damage to the small unmyelinated peripheral nerve fibers. These fibers categorized as C fibers are present in skin peripheral nerves and organs.