Rheumatoid arthritis is an autoimmune disorder that causes chronic inflammation in the small joints of the hands and feet. The inflammation causes painful swelling and results in joint deformity. About 2 in 100 men and 4 in 100 women develop rheumatoid arthritis.
It usually begins after age 40, but can occur also at earlier ages. It is estimated that two-thirds of the risk for rheumatoid arthritis is genetic in origin. The genetic makeup does not really cause the disease, but it makes a person more susceptible to environmental factors.
The triggers for rheumatoid arthritis may be bacterial or viral infections. One of the major risk factors is smoking. Rheumatoid arthritis cannot be cured; the treatment aims at reducing the number and severity of flares (worsening of symptoms) and preventing long-term damage to the joints.