Persistent and severe shoulder pain, often due to dislocation of the shoulder joint. There is a clear history of trauma. In traumatic anterior shoulder dislocation, there is a clear history of trauma, shoulder pain, swelling and dysfunction, and the injured limb is flexibly fixed in a mildly abducted internal rotation position with the elbow flexed and the affected forearm supported by the healthy hand. What are the possible diseases that cause persistent and severe shoulder pain? 1. Shoulder dislocation Shoulder dislocation is the most common, accounting for about 50% of all joint dislocations, which is related to the anatomical and physiological characteristics of the shoulder joint, such as the large humeral head, shallow and small joint pelvis, loose joint capsule, weak tissue below the front, large range of joint movement, and more opportunities to suffer from external forces. Shoulder dislocation occurs mostly in young adults and more often in men. 2. Congenital shoulder dislocation Congenital shoulder dislocation is extremely rare, and there are only a few case reports in the literature. Only if the shoulder dislocation is found at birth, it is congenital, i.e. the diseased joint dislocation is formed in the womb. Those seen clinically are often paralytic, mostly due to paralysis of the shoulder muscles, such as a birth brachial plexus injury. Traumatic dislocation of the shoulder joint in the neonatal period almost never occurs. 3. Humeral head fracture A simple humeral head fracture is relatively rare and is an intra-articular fracture, mainly due to indirect external forces. Fractures are mostly seen in young adults and occasionally in the elderly. Depending on the extent of the fracture, there are three types of humeral head fracture, humeral head fracture dislocation and humeral head comminuted fracture. 4.Frozen shoulder Frozen shoulder is a chronic and specific inflammation of the shoulder capsule and its surrounding ligaments, tendons and bursa, which is characterized by gradual pain in the shoulder, especially at night and gradually aggravated by the limitation of the shoulder joint function, and gradually relieved to a certain degree until finally completely recovered.