What is the median nerve?

The median nerve runs down the front of your lower arm (forearm) to your wrist. It helps control feeling and movement in your forearm, wrist and hand. If it becomes compressed (pinched) as it passes through a part of your wrist called the carpal tunnel, it causes a condition called carpal tunnel syndrome. This can lead to pain and weak muscles in your arm, wrist and hand. Carpal tunnel syndrome is often due to a repetitive use injury that causes swelling and narrowing in the carpal tunnel (for example, frequent use of a computer mouse or keyboard). Some health conditions, such as pregnancy, diabetes and rheumatoid arthritis can also raise your risk.