Rheumatoid arthritis (RA) Glossary

Analgesic—Also known as a painkiller, such as acetaminophen. These generally don't affect inflammation.

Antibody—A substance created by white blood cells that the immune system uses to fight infections.

Autoimmune disease—A kind of disease where the body's immune system doesn't work the way it should. Instead of only providing protection from harmful events, such as infections, the immune system attacks the body as well. Examples of autoimmune diseases are RA and lupus.

B cell—A type of white blood cell. Some B cells make the antibody called rheumatoid factor (RF).

Biologic DMARD (disease modifying antirheumatic drug)—The newest type of medicine to treat the signs and symptoms of RA. These drugs block the action of certain substances in the body and may be able to slow down the progression of RA. Biologic DMARDs are produced from living cells.

Bursitis—Inflammation of the bursa, a pouch or sac near a bone.

CCP (cyclic citrullinated peptide)—A substance found naturally in the blood. In some people with RA, the body forms an antibody that attacks CCP. This may help cause inflammation.

CRP (C-reactive protein)—A substance found in the blood that indicates that there is inflammation in the body. For people with RA, doctors frequently measure the amount of CRP.

Cytokines—Substances in the blood that communicate with white blood cells. Some of these cytokines organize the attack on infections, which results in inflammation. When the immune system is working normally, the attack is ended once the infection has been fought off. However, people with RA have levels of certain cytokines that are too high. It's this constant inflammation that causes the signs and symptoms of rheumatoid arthritis. Major cytokines that play a role in RA are TNF (tumor necrosis factor), IL-1 (interleukin 1) and IL-6 (interleukin 6).

DMARD (disease modifying antirheumatic drug)—A kind of medicine that works on the immune system to treat the signs and symptoms of RA and may slow the progression of the disease.

Erythrocyte sedimentation rate (ESR)—A blood test doctors use to help diagnose RA. Erythrocyte sedimentation rate (ESR) measures inflammation by seeing how long it takes red blood cells to fall to the bottom of a test tube filled with blood. The red blood cells generally fall faster in people with inflammation than in those without. The test can't diagnose RA by itself, but about 60% of people with a high ESR do have RA.

Family doctor—A doctor whose practice is not limited to any specific branch of medicine or class of diseases. These doctors can also be called a general practitioner, family practitioner or primary care physician.

Fatigue—A general feeling of exhaustion or weariness. Fatigue can be caused by inflammation or disease, lack of sleep or physical, mental or emotional overexertion.

Fibromyalgia—A condition sometimes confused with RA. People with fibromyalgia mostly have pain and stiffness across many large muscle groups.

Flare or Flare-up—A sudden recurrence of the signs and symptoms of a disease.

Gout—A condition sometimes confused with RA. High amounts of uric acid, a waste product in the body, form crystals in the joints. In people with this condition, the body isn't able to get rid of the extra uric acid. These crystals lead to inflammation and extreme pain, often in the big toe. More common in men than women.

HLA (human leukocyte antigen)—Proteins on the surface of white blood cells that distinguish foreign cells versus the body's own cells.

IL-1—An abbreviation for interleukin 1. Interleukins are also cytokines. IL-1 is a cytokine that plays a role in the immune system. People with RA have too much IL-1 in their systems, which is a factor in inflammation.

IL-6—An abbreviation for interleukin 6. In people with RA, there is more IL-6 in the lining of the joints than any other cytokine.

Immune system—A complex collection of organs and cells that protect the body from foreign substances such as bacteria and viruses. In people with RA, the immune system becomes too active and starts to harm the body as well.

Inflammation—Occurs when the immune system defends the body against harmful events. Results in pain, swelling, redness and heat. Chronic inflammation is a symptom of RA.

Infusion—Delivery of liquid medication through a needle directly into a vein. Also known as an intravenous (IV) infusion.

Infusion nurse—A nurse who administers and monitors the infusion process.

Injection—Like other shots you might get in your doctor's office. Liquid medication is given through a needle either under the skin (subcutaneous) or into a joint.

Joint—The place where two bones meet.

Joint Count—An examination performed by a doctor to determine the number of joints affected by rheumatoid arthritis.

Lupus—A condition sometimes confused with RA. It causes pain and inflammation in the muscles and joints. Also called systemic lupus erythematosus. Lupus can damage organs such as the kidney. People with Lupus may also have joint pain and a certain skin rash.

Lyme disease—A condition sometimes confused with RA. Caused by a bacteria carried by ticks. Usually starts with a rash and a fever, but can affect the joints if not treated.

NSAID (nonsteroidal anti-inflammatory drug)—A type of medicine that relieves the pain and inflammation. Some NSAIDs are available over the counter, such as ibuprofen or naproxen, but others require a prescription.

Osteoarthritis (OA)—A condition that can be confused with RA. Damage to joints is usually caused by the wear and tear of age.

Patient advocate—An individual that you choose to be part of your healthcare team to partner with you in your discussions with the doctor. A patient advocate can be a family member, trusted friend or someone who is knowledgeable about your condition or the healthcare industry in general.

Physical therapist—A person who uses massage, heat treatment, exercise and other physical methods to help restore function and prevent disability in people with RA and other conditions.

Psychologist—A person who is trained in mental health and treatment through therapy of emotional disorders.

Rheumatologist—A doctor who specializes in diseases that affect the joints. The rheumatologist is the expert in treating bone and joint diseases like RA.

Rheumatoid arthritis (RA)—A long-term condition where the body's immune system attacks not only foreign substances like bacteria and viruses, but also attacks the body itself. It results in symptoms including joint pain, joint stiffness, fatigue and others that may affect the entire body.

Rheumatoid factor (RF)—A substance found in the blood of 70-80% of people with RA. Helps doctors diagnose RA because there may be more RF present as RA becomes more severe.

Social worker—A person who is trained to help people with social and economic problems.

Steroid—A type of medicine that reduces the pain and inflammation of RA but has limited ability to reduce joint damage. Steroids can be taken as pills or as an injection directly into a joint. A common steroid taken by people with RA is prednisone.

Synovial fluid—Clear fluid produced by the synovium that lubricates the cartilage and bones inside the joint so that the bones can move with ease.

Synovitis—Inflammation of the synovium, or lining of the joint.

Synovium—The connective tissue that lines the joint capsule and produces synovial fluid.

T cell—A type of white blood cell. T cells are also very important for fighting infections. There are different kinds of T cells, each with a different function. In people with RA, for reasons that aren't really known, T cells responsible for inflammation are seen in large numbers.

TNF—An abbreviation for tumor necrosis factor. TNF is a cytokine. In people with RA, TNF plays a large role in the immune system and maintaining inflammation.

White blood cells—Part of the immune system, they are cells in the body that help to fight infection.

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