Motor neuropathy can cause calluses, hammertoes, and other deformities, which can in turn lead to ulcers or painful walking. Autonomic neuropathy can impair sweating and cause dryness in the feet. In addition, autonomic neuropathy can cause orthostatic hypotension and gastrointestinal problems, including diarrhea and constipation. Neuropathy can also cause severe muscle weakness, leading to permanent disability unless muscles are maintained through exercise, which should include passive range-of-motion exercise