Pain, weakness or numbness in the hand and wrist that radiates up the arm could be a sign of carpal tunnel syndrome. This condition begins when the median nerve, which runs from the forearm into the palm of the hand, becomes pressed or squeezed at the wrist.
In essence, the median nerve controls sensations to the palm side of the thumb and fingers (excluding the little finger) as well as impulses to some small muscles in the hand that allow the fingers and thumb to move.
The carpal tunnel - a narrow passageway of ligament and bones at the base of the hand - houses the median nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed.
Although painful sensations may indicate other conditions, carpal tunnel syndrome is the most common and widely known of the entrapment neuropathies where the body's peripheral nerves are compressed.
Symptoms usually start gradually, with frequent burning, tingling, or itching numbness in the palm of the hand and the fingers, especially the thumb and the index and middle fingers.