Rheumatoid arthritis (RA) is a chronic autoimmune disorder that primarily affects the joints, causing inflammation, pain, and stiffness.

Unlike osteoarthritis, which is caused by wear and tear on the joints, rheumatoid arthritis occurs

when the body’s immune system mistakenly attacks its own tissues, particularly

the synovium—the lining of the joints. Over time, this inflammation can damage the cartilage and bones within the joints, leading to deformities and limited mobility.

While RA most commonly affects the hands, wrists, and knees, it can involve any joint in the body and even affect other systems, such as the skin, eyes, and lungs.