The carpal tunnel, a passageway through the wrist, carryies tendons and one of the hand’s major nerves. Pressure may build up within the tunnel because of disease (such as rheumatoid arthritis), fluid retention during pregnancy, injury, overuse, or repetitive motions. This pressure on the nerve within the tunnel causes a tingling sensation in the hand, often accompanied by numbness, aching, and impaired hand function, which is known as carpal tunnel syndrome.
Carpal tunnel syndrome can cause a dull ache, numbness or tingling in the shaded area shown in the illustrations below.
(Pict. 01 to 03)