Rheumatoid arthritis is a chronic inflammatory disorder that typically affects the small joints in your hands and feet. Unlike the wear-and-tear damage of osteoarthritis, rheumatoid arthritis affects the lining of your joints, causing a painful swelling that can eventually result in bone erosion and joint deformity.
An autoimmune disorder, rheumatoid arthritis occurs when your immune system mistakenly attacks your own body’s tissues. In addition to causing joint problems, rheumatoid arthritis can also affect your whole body with fevers and fatigue.
Rheumatoid arthritis is much more common in women than in men and generally occurs between the ages of 40 and 60. Treatment focuses on controlling symptoms and preventing joint damage.
Rheumatoid arthritis occurs when your immune system attacks the synovium — the lining of the membranes that surround your joints. The resulting inflammation thickens the synovium, which can eventually invade and destroy the cartilage and bone within the joint. The tendons and ligaments that hold the joint together weaken and stretch. Gradually, the joint loses its shape and alignment.
Doctors don’t know what starts this process, although a genetic component appears likely. While your genes don’t actually cause rheumatoid arthritis, they can make you more susceptible to environmental factors — such as infection with certain viruses and bacteria — that may trigger the disease.