This degenerative joint disease is common in people over 65, but may appear decades earlier. Rheumatoid arthritis, which affects 2.5 million Americans, can strike at any age, but usually appears between ages 20 and 50. Any joint can be affected, but the feet, knees, hips, and fingers are most common. It may appear in one or two joints and spread no further. In rheumatoid arthritis, the hands are most commonly affected, but it can affect most joints of the body.
Inflammation begins in the synovial lining and can spread to the entire joint.
Painful and knobby bone growths in the fingers are common, but usually not crippling to osteoarthritis. The disease is often mild, but can be quite severe. For sufferers of rheumatoid arthritis, though, arthritis is highly variable and difficult to control and can severely deform joints. Some people become bedridden. Others continue to run marathons.