Frozen shoulder is usually caused by soft tissue degeneration, acute and chronic shoulder injury. 1. Degenerative changes of soft tissues: Frozen shoulder occurs mostly in people aged 40 to 60 years old, due to the degenerative changes of the glenoid and humeral head as well as the joint capsule at this time, which is the basis of the occurrence of frozen shoulder. 2. Acute and chronic injuries of shoulder: Shoulder tissues may be strained when repeated or prolonged abduction, lifting and internal rotation of the upper arm are carried out for a long period of time. In addition, if acute injury occurs in the shoulder joint, such as early treatment is not proper, it may also induce frozen shoulder. Frozen shoulder has many causes, and it needs to be treated at an early stage after the occurrence of frozen shoulder, paying attention to the functional exercise, and also hot compresses and physiotherapy, so that the prognosis is good.