Rheumatoid arthritis (RA) is a chronic (long-term) disease. The symptoms can come and go, and each person with RA is affected differently. Some people have long periods of remission. Their rheumatoid arthritis is inactive, and they have few or no symptoms during this time. Other people might have near-constant symptoms for months at a stretch.

Although rheumatoid arthritis can involve different parts the body, joints are always affected. When the disease acts up, joints become inflamed. Inflammation is the body's natural response to infection or other threats, but in rheumatoid arthritis inflammation occurs inappropriately and for unknown reasons.