Rheumatoid arthritis is a disease that affects the joints. It causes pain, swelling, and stiffness. If one knee or hand has rheumatoid arthritis, usually the other does, too. This disease often occurs in more than one joint and can affect any joint in the body. People with this disease may feel sick and tired, and they sometimes get fevers.
RA is an autoimmune disease, which means the arthritis results from your immune system attacking your body's own tissues.
The course of rheumatoid arthritis can range from mild to severe. In most cases it is chronic, meaning it lasts a long time—often a lifetime. For many people, periods of relatively mild disease activity are punctuated by flares, or times of heightened disease activity. In others, symptoms are constant.
Scientists estimate that about 1.3 million people in the United States have rheumatoid arthritis.
Who Gets Rheumatoid Arthritis?
The disease occurs in all racial and ethnic groups, but affects two to three times as many women as men. Rheumatoid arthritis is more commonly found in older individuals, although the disease typically begins in middle age. Children and young adults can also be affected.
How Is Rheumatoid Arthritis Diagnosed?
People can go to a family doctor or rheumatologist to be diagnosed. A rheumatologist is a doctor who helps people with problems in the joints, bones, and muscles. Rheumatoid arthritis can be hard to diagnose because:
- There is no single test for the disease.
- The symptoms can be the same as other kinds of joint disease.
- The full symptoms can take time to develop.
To diagnose rheumatoid arthritis, doctors use medical history, physical exam, X-rays, and lab tests.
Rheumatoid arthritis is different from osteoarthritis, the common arthritis that often comes with older age. RA can affect body parts besides joints, such as your eyes, mouth, and lungs.
What Causes Rheumatoid Arthritis?
Doctors don't know the exact cause of rheumatoid arthritis. They know that with this arthritis, a person's immune system attacks his or her own body tissues. Researchers are learning many things about why and how this happens. Things that may cause rheumatoid arthritis are:
- Genes (passed from parent to child)