Types of Arthritis

There are more than 100 different types of arthritis. Some of the more common types include:

Osteoarthritis.

This is the most common type of arthritis. It occurs when the cartilage covering the end of the bones gradually wears away. Without the protection of the cartilage, the bones begin to rub against each other and the resulting friction leads to pain and swelling. Osteoarthritis can occur in any joint, but most often affects the hands and weight-bearing joints such as the knee, hip and facet joints (in the spine). Osteoarthritis often occurs as the cartilage breaks down, or degenerates, with age. For this reason, osteoarthritis is sometimes called degenerative joint disease.

Rheumatoid arthritis.

Rheumatoid arthritis is a long-lasting disease that can affect joints in any part of the body but most commonly the hands, wrists, and knees. With rheumatoid arthritis, the immune system -- the body's defense system against disease -- mistakenly attacks itself and causes the joint lining to swell. The inflammation then spreads to the surrounding tissues, and can eventually damage cartilage and bone. In more severe cases, rheumatoid arthritis can affect other areas of the body, such as the skin, eyes, and nerves.

Gout.

Gout is a painful condition that occurs when the body cannot eliminate a natural substance called uric acid. The excess uric acid forms needle-like crystals in the joints that cause swelling and severe pain. Gout most often affects the big toe, knee and wrist joints.