FAQ: What Is Rheumatoid Arthritis?

Rheumatoid arthritis is a chronic disease that usually affects the lining of certain joints, especially those in the hands. The related inflammation often causes pain and swelling and, if left untreated, can result in permanent damage to the joints and in eventual disability.

Rheumatoid arthritis is an autoimmune disease, which means that it's caused by the body's immune system incorrectly attacking certain parts of the body. The cause of rheumatoid arthritis isn't well understood, although experts suspect a combination of genetic factors and environmental triggers. Rheumatoid arthritis is more common in women than in men, and it's usually diagnosed in people aged 30 to 60.

Although joint pain is the most common symptom, rheumatoid arthritis can also cause other symptoms. These may include:

• Morning stiffness, lasting an hour or more.

• Fatigue, fever, and/or weight loss.

• Firm bumps under the skin (known as nodules), which are usually painless but can be tender.

The symptoms of rheumatoid arthritis, like those of many autoimmune diseases, often wax and wane on their own. Doctors refer to this as the rheumatoid arthritis being more or less "active."

It's important to get rheumatoid arthritis diagnosed early, since treatment of the inflammation can help stop or delay joint damage and can control symptoms.