Carpal tunnel refers to the area within the wrist and adjacent palm, through which tendons that connect forearm muscles to the fingers pass through. There are 9 tendons (1 for thumb and 2 for each finger) which keep on sliding through the tunnel as we move our fingers during all kinds of activities. There is also a single nerve (median nerve), which passes through the tunnel. It carries sensations (feelings) from the thumb, index finger, middle finger and adjacent part of ring finger. It also makes the muscles that are responsible for moving the thumb.
Carpal tunnel syndrome refers to a group of symptoms resulting from pressure on the median nerve within the carpal tunnel. Initial symptoms are related to malfunction of nerve components that carry sensations from the fingers and the thumb; the result may be tingling, numbness, burning sensations or the feeling that the “fingers are asleep” often forcing the person to move or shake the hand repeatedly. The symptoms may be worse at night causing sleep interruption. Worsening may also occur with activities like driving, holding the telephone to the ear or doing your hair. At the next stage, loss of feelings in the hand may be severe enough to cause accidentally dropping objects like cups or plates carried in the hand. With further worsening, the muscles at the base of the thumb starts to atrophy (Figure 1, 2) leading to weakness of the hand. For more information: Carpal tunnel syndrome