The Facts
Rheumatoid arthritis (RA) is a chronic condition that causes the lining of your joints or other body areas to become inflamed. As it progresses, it further damages the tendons, ligaments, cartilage, and bone in your joints. It may also damage other areas of the body, including the lungs or blood vessels.
About 1% of the population has RA, with women about 2 to 3 times more likely than men to get it. Although it can occur at all ages, people most often develop RA between the ages of 25 and 50 years.
Causes
Rheumatoid arthritis (RA) is an autoimmune disease. This means that the body's immune system fails to recognize its own tissue, and views it as a foreign invader. In the case of RA, the immune system attacks the joints and tissue, causing long-term damage.
It's hard to determine who will develop RA. It is believed that RA may be caused by a combination of factors, including genetic risk and environmental factors such as a bacterial or viral infection.