Peripheral neuropathy (peripheral nerve disease) is a disorder affecting one or more peripheral nerves. There are many causes, including systemic disease (eg, diabetes [type 1, type 2], metabolic syndrome), genetic disorders (eg, Charcot-Marie-Tooth disease, Friedreich ataxia, amyloidosis), inflammatory / autoimmune disease (eg, Guillain-Barré syndrome, Sjögren disease), infection (eg, human immunodeficiency virus [HIV], leprosy, hepatitis C), vitamin and nutritional deficiencies (eg, vitamin B12 deficiency, copper deficiency), drugs or toxins (eg, chemotherapy, fluoroquinolones, alcohol), trauma, or compression injuries. Damage can occur in sensory, motor, and/or autonomic nerves, and symptoms depend on the nerves affected.

Common signs and symptoms depend to some extent on the class of peripheral nerves involved and include burning pain, numbness or tingling (often due to small fiber involvement), weakness, muscle atrophy, fasciculations, imbalance or difficulty walking, impaired joint position or vibratory sense (mostly due to large fiber involvement), or autonomic dysfunction including orthostatic hypotension, urinary incontinence, sexual dysfunction, or sweating abnormalities (due to autonomic fiber involvement). While many peripheral neuropathies can affect all fibers, some disorders cause pathology in one class more profoundly than the others. Thus some patients may have some or most of these symptoms. Progressive neuropathy in the lower extremities can lead to foot ulcerations (neurogenic ulcer), arthropathy with formation of Charcot joints, and increased risk of skin infections and osteomyelitis.