There are many reasons for shoulder swelling, and the common causes are as follows: 1. Neurogenic cervical spondylosis, which occurs when a protruding intervertebral disc compresses the sphenopalatine nerve root in the neck, resulting in soreness and numbness in the shoulder, upper arm, and even forearm. 2. Chronic strain injury of the shoulder, which occurs when the patient suffers from long-term strain injury of the shoulder, resulting in fasciitis of the latissimus dorsi, trapezius, and other muscles in the shoulder, resulting in soreness and pain in the shoulder. 3. This is a common disease that occurs in middle-aged and elderly patients. The cause of this disease is unknown, and it often manifests itself as a restriction in the movement of the shoulder joint in all directions. For these types of disorders, it is recommended that the patient visit an orthopedic clinic, where the physician can give an accurate judgment based on the patient’s clinical presentation, physical examination and, if necessary, comprehensive imaging examinations.