what is rheumatoid arthritis disease
Share +. Text A A A. Rheumatoid arthritis (RA) is an autoimmune disease where the body's immune system attacks normal joint tissues, causing inflammation of the joint lining. This inflammation of the joint lining (called the synovium) can cause pain, stiffness, swelling, warmth, and redness.ext A A A. Rheumatoid arthritis (RA) is an autoimmune disease where the body's immune system attacks normal joint tissues, causing inflammation of the joint lining.