In Rheumatoid Arthritis (rue-ma-toyd are-thry-tis),an abnormality in the body's defense or immune system causes inflammation of the joints. Inflammation begins in the joint lining and then may damage both cartilidge and bone. It causes pain, stiffness, swelling and loss of function in the joints. The involved joints can lose their shape and alignment, which results in pain and loss of movement. RA often affects the same joints on both sides of the body. The hands, wrists, feet, knees, ankles, shoulders, neck, jaw and elbows can be affected. RA is more common in women than in men.

What causes it? The cause of RA is not known. Recent studies show that some people inherit a tendency to develop RA. Many people with RA have a gene marker called HLA-DR4.

How is it diagnosed? Doctors diagnose RA based on treatment, medical history, physical exam, X-rays and blood tests for an antibody known as rheumatoid factor.

How is it treated? Treatment of RA focuses on reducing swelling, relieving pain and stiffness, reducing inflammation and maintaining joint function. Treatments include anti-inflamatory drugs, glucocorticoids, disease modifying drugs, biologic response modifiers, exercise, rest, joint protection, self-help skills and sometimes surgery.