Carpal tunnel syndrome is a painful illness of the hand and wrist. It is caused by a gradual compression of the median nerve, which runs from the forearm into the hand. The median nerve is responsible for controlling some of your hand muscles and allowing you to feel sensations with your hand. As this nerve is squeezed, less blood and nutrients flow to it. This can cause pain, numbness, and weakness in the fingers and thumb. As carpal tunnel syndrome progresses, it can become difficult to form a fist, grasp small objects, or perform manual tasks. The risk of developing carpal tunnel syndrome is not confined to people in a single industry or job, but the condition is especially common in those performing assembly line work (such as manufacturing, sewing, and finishing).