Causes of Rheumatoid Arthritis

In rheumatoid arthritis (RA), the joint lining swells, invades surrounding tissues, and produces chemical substances that attack and destroy the joint surface. RA typically affects joints on both sides of the body in the hands and feet, as well as the hips, knees, and elbows. Without proper treatment, RA can become a chronic, disabling condition.

An infection or environmental factor can activate specific genes that some people possess, triggering the development of RA. When the body is exposed to such a trigger, the immune system responds inappropriately. Instead of protecting the joint, the immune system begins to produces substances that attack the joint.