Entrapment neuropathies occur in a number of different but predictable locations in the upper extremity. These neuropathies can produce a spectrum of sensory and motor deficits in the hand and upper extremity. A careful clinical examination in conjunction with electromyography and nerve conduction velocity studies can usually delineate peripheral nerve dysfunction. Prognosis depends on the degree of nerve injury, which is related to both the cause and the duration of the entrapment.