Tenosynovitis of the thumb is more common in clinical practice and can be caused by injury, overexertion, and some immune disorders. Overexertion is most commonly seen in osteoarthritis of the thumb, elbow, and fingers. In addition, infections can also cause tenosynovitis, which is called bacterial tenosynovitis. The disease can be triggered or exacerbated by occupations that require repetitive strain on the joints for long periods of time, such as typists, keyboard players, instrumentalists, cargo handling, or industries that require long hours of computer operation. Commonly affected areas include the wrists, fingers and shoulders. Women and diabetics are more likely to suffer from the disease. Patients may experience joint pain and morning stiffness, which is usually most pronounced after waking up, and the symptoms do not ease significantly with frequent activity. The affected joints may become swollen or even pop, and joint movement is impaired. Flexor tendon tenosynovitis occurs in the thumb, ring finger, index and middle fingers, and the elbow. Patients may experience flexion and extension dysfunction, which is particularly noticeable upon waking in the morning and may decrease or disappear with activity. When bending the affected finger, it suddenly stays in the semi-bending position, the finger can neither be straightened nor flexed, and the pain is as unbearable as if it was suddenly stuck, and the finger can only move after the other hand helps to trigger it, producing the same action as a trigger, so it is also called trigger finger.