Nine tendons that control the fingers pass through the carpal tunnel, along with the median nerve. Pressure will build up in this space if the tendons become inflamed or if the wrist is held in an awkward position. This increased pressure can interrupt the blood flow to the median nerve. Over time, restricted blood flow damages the nerve. The disorder can affect either hand or both hands, and onset is usually gradual.
Initial symptoms are pain, tingling and numbness, often occurring at night.
The symptoms usually occur in the first three fingers and the palmar side of the thumb. Loss of sensation, motor weakness, dry skin, loss of coordination, and atrophy are later symptoms. Occupational Risk Factors Highly repetitive work. Bent wrist postures. Excessive force, especially in conjunction with highly repetitive work and deviated postures.