(1) What is rheumatoid arthritis (RA)?

RA is one kind of arthritis (Arthritis means inflammation of joints). About 1 in 100 people develop RA at some stage in their lives. It can happen to anyone. It is not an hereditary disease. It can develop at any age, but most commonly starts between the ages of 40 and 60. It is about three times more common in women than in men.