There are more causes of thumb pain, which may be related to trauma, tenosynovitis, rheumatoid arthritis and other causes. 1. Trauma: due to mechanical injury or sharp objects and other injuries, the ligaments and muscles around the thumb or the thumb joint capsule are damaged, which is manifested as swelling of the thumb joint, restricted movement, pain and other symptoms. 2. Tenosynovitis: Prolonged holding the mouse, one-handed operation of the cell phone screen and other overuse of the thumb, resulting in prolonged and repeated friction and irritation of the thumb tendon, causing inflammation of the thumb tendon sheath, manifested as pain in the thumb. 3. Rheumatoid arthritis: due to genetic, infections and other reasons, resulting in the immune system, attacking the joints, the joint tissue is gradually eroded. This results in redness, swelling, pain and limited movement of the thumb joint. Thumb pain can also be seen in osteophytes and other causes, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, and targeted treatment or therapy.