Pain occurs in the joints of the arm, and the following reasons are common: 1. If it is an elderly patient, it is mostly osteoarthritis of the elbow joint and synovitis, which are degenerative changes. Therefore, there will be elbow joint pain, activity limitation, in flexion and extension activities, there will be intra-articular noise, mainly the sound of articular cartilage friction, the patient will also have joint swelling and joint effusion, and the joint skin temperature will gradually increase.2. If the patient is a young patient, most of them have elbow joint injury, and the young patients like to play sports, and their elbow joints may be damaged in the process of exercise, which will lead to pain in the left elbow joint, Swelling and transient activity limitation. Generally, after active treatment, such as cold compresses, braking, elevation, etc., the pain, swelling and other clinical symptoms will be gradually relieved.