Polyneuropathy is a frequent complication of diabetes; it affects most individuals after prolonged hyperglycemia, and diabetic neuropathy is very common in the developed world. Chronic, insidious, distal sensorimotor polyneuropathy with autonomic impairment is the most typical form of diabetic neuropathy. Less common, but more florid presentations include autonomic symptoms or painful neuropathy. Although many patients have no or relatively few symptoms, the chronic polyneuropathy and autonomic dysfunction predispose to neurotrophic foot ulceration; consequently, diabetes is the leading cause of amputation today.