Pain under the thumb is more commonly caused by trauma to the muscles under the thumb, or by abnormal strain on the thumb, which may cause damage to the thumb and result in pain under the thumb. The pain may also be caused by prolonged cold that causes pain in the muscles under the thumb or by propping the palm of the hand on the ground, causing ischemic changes in the area, which may also cause pain in this area. Pain under the thumb may be caused by excessive movement of the thumb, or by tendinitis due to overload or incorrect use of the thumb. It can also be caused by prolonged compression of the wrist or hand resulting in entrapment of the median nerve at the wrist, which can also cause corresponding muscle pain under the thumb. In addition, patients who do excessive gripping with their hands may also cause intrinsic muscle fatigue, at which point pain under the thumb may occur.