Laboratory Evaluation of Peripheral Neuropathy.

This review explains how to choose lab tests for peripheral neuropathy based on the pattern of nerve involvement (for example, length‑dependent sensory neuropathy, small‑fiber/autonomic neuropathy, acute vs chronic, symmetrical vs focal) instead of ordering large, nonspecific panels. The authors provide algorithms that start with a targeted high‑yield core workup (e.g., diabetes screening, B12 and other key vitamins, thyroid tests, basic autoimmune and paraprotein screens) and then add more specialized tests only when the clinical pattern suggests specific causes (e.g., immune, genetic, toxic, infectious). They emphasize avoiding expensive, low‑yield bundled antibody panels unless clearly indicated, to reduce cost and patient burden. For patients with conditions like POTS, EDS, or MCAS—who often have small‑fiber or autonomic neuropathy—this paper supports a structured, stepwise lab approach that focuses on identifying treatable causes (such as autoimmune, nutritional, metabolic, or paraproteinemic neuropathies) rather than indiscriminate testing, thereby improving the chances of finding actionable diagnoses and guiding therapy.