The usual causes are direct trauma, prolonged pressure on the nerve, and compression of the nerve by nearby body structures. Entrapment involves pressure on the nerve where it passes through a narrow structure. Wrist fractures may injure the median nerve. In some cases, no detectable cause can be identified. This is a fairly common occupational or recreational injury.
Prevention varies depending on the cause.
Avoid prolonged repetitive movement of the wrist. In occupations that require repetitive wrist movements, change in the way the job is performed may be necessary. There may be weakness of the thumb and difficulty with opposition of the thumb and little finger. A detailed history may be needed to determine the possible cause of the neuropathy. Tests are guided by the suspected cause of the dysfunction as suggested by the history, symptoms presented, and pattern of symptom development.