Carpal tunnel syndrome is a common condition that causes pain and tingling in the forearm and hand. This condition is caused by a compression of the median nerve, which innervates the palm side of the thumb, index finger, and part of the ring finger. This is most often an overuse injury, frequently caused by daily activities such as computer and phone use. This overuse causes irritation and swelling of the carpal tunnel, which houses the median nerve. This may result in weakness, pain, numbness, and tingling of the hand, wrist, and forearm.