Browse by condition.

Raynaud's Phenomenon

Raynaud's Syndrome

Reactive Arthritis

Recurrent miscarriage

Recurrent UTI

Renal Tubular Acidosis

Resistant Hypertension

Rhabdomyolysis

Rheumatoid Arthritis (RA)

What Is Rheumatoid Arthritis? Causes, Signs & Symptoms, Diagnosis, Treatment, and Prevention What Is Rheumatoid Arthritis? Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease, which means that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body. 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. The inflammation associated with rheumatoid arthritis is what can damage other parts of the body as well. While new types of medications have improved treatment options dramatically, severe rheumatoid arthritis can still cause physical disabilities. Rheumatoid arthritis mainly attacks the joints, usually many joints at once. Rheumatoid arthritis commonly affects joints in the hands, wrists, and knees. In a joint with Rheumatoid arthritis, the lining of the joint becomes inflamed, causing damage to joint tissue.

Rotavirus Infection