There are differences between frozen shoulder and shoulder arthritis in terms of etiology, symptoms and location of onset. 1. Causes: Frozen shoulder is mainly caused by chronic inflammation and fibrosis of the soft tissues around the joint capsule due to over-exertion of the joints, long-term chronic injuries, degeneration, cold and other reasons. Most of the shoulder arthritis is due to traumatic arthritis caused by trauma, or bacterial invasion of the shoulder joint leads to septic arthritis of the shoulder joint, which can easily cause joint ligament and joint capsule edema. 2. Symptoms: Patients with frozen shoulder usually have pain around the shoulder, redness and swelling, limited shoulder joint movement, and in severe cases, it may lead to radiating pain in the back. In addition to shoulder pain, shoulder arthritis may also cause gradual stiffness of the shoulder joint. 3. Location: Frozen shoulder develops inflammatory lesions in the soft tissues around the shoulder joint. On the other hand, the scope of shoulder arthritis is larger than that of frozen shoulder, and it may appear in the position of glenoid, humeral head and surrounding soft tissues. Patients with shoulder discomfort symptoms should go to the hospital for relevant examinations in time, and follow the doctor’s instructions for systematic treatment after clarifying the cause of the disease.