Conditions InDepth: Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a common inflammatory disease that affects connective tissue throughout the body. The most common areas affected are the joints. A joint is the location where bones come together. Several structures work together to allow movement of the joint:
- Synovium—A capsule that surrounds and protects the joint. The tissue also produces a fluid that helps lubricate and protect the joint.
- Cartilage—Soft tissue that covers the ends of the bone to allow the bones to glide over each other smoothly.
- Tendons—Strong tissue that connects muscle to bone near the joint. The tendons cross over joints and are critical to allowing movement.
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- The lungs and the lining that surrounds them
- The heart and the lining that surrounds it
- Artery walls
- The whites of the eyes—sclera
CausesRA is an autoimmune disease. The immune system is designed to attack foreign substances in the body such as viruses or bacteria. With an autoimmune disorder, the immune system mistakenly identifies healthy body tissue as foreign tissue and attacks it. In RA, the joint tissue is attacked. This attack causes irritation and swelling in the synovium and a thickening of the fluid in the joint which causes the hallmark redness, swelling, and stiffness of the joints. Over time, this constant inflammation wears away at the cartilage and bone inside the joint, and makes the nearby tendons weak, making movement painful and difficult. The exact cause of autoimmune disorders like RA is not known, but is believed to be a combination of:
- Genetic factors—faulty genes may redirect immune system to attack specific healthy tissue
- Environmental factors—may trigger gene defect and/or cause change in immune system
- Chemical or hormonal imbalances in the body
Handout on health: Rheumatoid arthritis. National Institute of Arthritis and Musculoskeletal and Skin Diseaseswebsite. Available at: http://www.niams.nih.gov/Health%5FInfo/Rheumatic%5FDisease/default.asp. Updated August 2014. Accessed October 29, 2014.
Rheumatoid arthritis. Arthritis Foundation website. Available at: http://www.arthritis.org/conditions-treatments/disease-center/rheumatoid-arthritis. October 29, 2014.
Rheumatoid arthritis. The Merck Manual Professional Edition website. Available at: http://www.merckmanuals.com/professional/musculoskeletal%5Fand%5Fconnective%5Ftissue%5Fdisorders/joint%5Fdisorders/rheumatoid%5Farthritis%5Fra.html. Updated May 2013. Accessed October 29, 2014.
Rheumatoid arthritis (RA). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated April 10, 2014. Accessed October 29, 2014.
Wasserman AM. Diagnosis and management of rheumatoid arthritis. Am Fam Physician. 2011;84(11):1245-1252.
- Reviewer: Michael Woods, MD
- Review Date: 05/2014
- Update Date: 10/29/2014