Rheumatoid arthritis (RA) is a systemic disease, which means it can affect many parts of the body. Joints are often involved including the wrists, knees, and hands. Any joint can become involved. There can also be changes in the heart, eyes, lungs, kidneys, and other soft tissues.

In 90 per cent of patients with RA, shoulder symptoms begin after five years. Tissue swelling and inflammation damage the cartilage, bone, and muscles. For many patients, early treatment with drugs and physical therapy is helpful. Treatment can help prevent RA from causing permanent damage.