The thumb is involved in about 50% of all hand functions. When the thumb is painful or injured, it becomes very difficult to use the hand. During normal life, we take our thumbs for granted. When the thumb is not working properly, tasks are more difficult, and we then realize how important the thumb is. There are several causes of thumb pain including: (1) trigger thumb, (2) arthritis, (3) tendonitis, (4) carpal tunnel syndrome, and (5) skier’s thumb.