Rheumatoid arthritis (RA) is an autoimmune disease in which the body’s immune system – which normally protects its health by attacking foreign substances like bacteria and viruses – mistakenly attacks the joints. This creates inflammation that causes the tissue that lines the inside of joints (the synovium) to thicken, resulting in swelling and pain in and around the joints. The synovium makes a fluid that lubricates joints and helps them move smoothly.
If inflammation goes unchecked, it can damage cartilage, the elastic tissue that covers the ends of bones in a joint, as well as the bones themselves. Over time, there is loss of cartilage, and the joint spacing between bones can become smaller. Joints can become loose, unstable,painful and lose their mobility. Joint deformity also can occur. Joint damage cannot be reversed, and because it can occur early, doctors recommend early diagnosis and aggressive treatment to control RA.
Rheumatoid arthritis most commonly affects the joints of the hands, feet, wrists, elbows, knees and ankles. The joint effect is usually symmetrical. That means if one knee or hand if affected, usually the other one is, too. Because RA also can affect body systems, such as the cardiovascular or respiratory systems, it is called a systemic disease. Systemic means “entire body.”
Rheumatoid arthritis is an autoimmune condition, which means it's caused by the immune system attacking healthy body tissue. However, it's not yet known what triggers this.
Your immune system normally makes antibodies that attack bacteria and viruses, helping to fight infection.
If you have rheumatoid arthritis, your immune system mistakenly sends antibodies to the lining of your joints, where they attack the tissue surrounding the joint.
In the early stages, people with RA may not initially see redness or swelling in the joints, but they may experience tenderness and pain.
These following joint symptoms are clues to RA:
Joint pain, tenderness, swelling or stiffness for six weeks or longer
Morning stiffness for 30 minutes or longer
More than one joint is affected
Small joints (wrists, certain joints of the hands and feet) are affected
The same joints on both sides of the body are affected.