Shoulder swelling is mainly due to the following reasons: 1. Due to a strain in the shoulder joint position, such as the shoulder joint position has not been sufficiently warmed up, when carrying out lifting, lifting heavy objects, due to the sudden excessive force, it will lead to more than the normal load of muscle tissue, so there will be a strain of muscle fibers, after the strain will produce more bruising, already inflammatory edema, which will see the shoulder joint 2. A fracture or dislocation around the shoulder joint can also lead to a greater amount of local blood leakage, which can also lead to swelling of the joint. 3. It may be due to an accumulation of fluid in the shoulder joint area, such as degeneration of the shoulder joint or bursitis. In case of strain, cold and excessive movements, synovitis and other sterile inflammatory lesions may occur, which may lead to the formation of local exudate and swelling of the shoulder joint. 4. Chronic sterile inflammatory lesions may form in the shoulder joint due to frequent strain and cold, and inflammatory metabolism may occur after cold and strain. The accumulation of inflammatory metabolic products after cold and strain may lead to inflammatory edema and swelling.