What Are the Types of Arthritis?

There are several types of arthritis. The two most common ones are osteoarthritis (AH-stee-oh-ar-THRY-tis) and rheumatoid (ROO-mah-toyd) arthritis.

Osteoarthritis is the most common form of arthritis. This condition usually comes with age and most often affects the fingers, knees, and hips. Sometimes osteoarthritis follows an injury to a joint. For example, a young person might hurt his knee badly playing soccer. Or someone might fall or be injured in a car accident. Then, years after the individual’s knee has apparently healed, he might get arthritis in his knee joint.

Rheumatoid arthritis happens when the body’s own defense system doesn’t work properly. It affects joints and bones (often of the hands and feet), and may also affect internal organs and systems. You may feel sick or tired, and you may have a fever.

Another common type of arthritis, gout, is caused by crystals that build up in the joints. It usually affects the big toe, but many other joints may be affected.

Arthritis is seen with many other conditions. These include:

- lupus (LOOP-us), in which the body’s defense system can harm the joints, the heart, the skin, the kidneys, and other organs
- an infection that gets into a joint and destroys the cushion between the bones.