Carpal tunnel syndrome is numbness and pain caused by pressure on the median nerve in the wrist that runs through the carpal tunnel, which narrows as a result of changes to bones or tendons in the wrist. Carpal tunnel syndrome usually manifests as numbness in the thumb, index, and middle finger. Pain is sometimes so severe that it interrupts sleep.

Carpal tunnel is common in people with jobs that require daily repetitive hand motions, like typing or heavy manual labor. It is seen more often in pregnant women, or people with diabetes or obesity. It can be diagnosed by a nerve conduction study to see if nerve signals are being slowed down due to compression. Treatment usually involves NSAIDs, wrist splints, and surgery in rare cases.