Video: What is Rheumatoid Arthritis?

Inflammation results from the body's normal response to wounds and infection. Rheumatoid arthritis, or RA, is an autoimmune disease. This means the body's immune system mistakenly attacks itself, causing inflammation and destroying tissue and bone.

Inflammation results from the body's normal response to wounds and infection. Rheumatoid arthritis, or RA, is an autoimmune disease. This means the body's immune system mistakenly attacks itself, causing inflammation and destroying tissue and bone.

RA mostly affects synovial joints. The ends of the bones are padded by soft tissue called cartilage and the whole joint is surrounded by an envelope of tissue called a joint capsule, which is lined with a synovial membrane.

In early RA, joint tissue swells, producing pain, stiffness, and redness. As it progresses, the synovial membrane thickens. Growth of inflamed synovial tissue begins as tissue normally produced for a healing wound. In RA this tissue, called pannus, can grow to invade and destroy cartilage and bone. In addition, inflamed cells can release enzymes that digest bone and cartilage. With continued destruction, bone joints no longer line up as they should. Then loss of muscle tissue occurs, with visible deformity. The invading tissue may harden, so the joint cannot move.

The hands, feet, wrists and other small joints are most commonly affected but RA can spread to anywhere in the body. Treatment is directed toward reducing inflammation and pain and preventing deformity and further joint destruction; the goal is the lowest possible level of disease activity and if possible, remission. Consulting a rheumatologist about treatment options is important for anyone with RA.

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