Carpal Tunnel Syndrome
The carpal tunnel is a tight, narrow, C-shaped passageway in the wrist that is made up of tiny bones and ligaments.
Some of the tendons and nerves that control movement of the fingers pass through the carpal tunnel into the hand. These tendons are covered with a fluid-filled sheath that helps them glide smoothly during movement. During repetitive hand motions, like typing, the tendons become irritated, causing swelling and inflammation within the sheath.
Because the carpal tunnel is made of bones and ligaments, it cannot expand to accommodate the swelling; this causes the nerves of the hand to become pinched or compressed, resulting in pain or numbness in the fingers.