Rheumatoid arthritis (RA) is a disease in which certain cells of the immune system malfunction and attack healthy joints.
RA causes inflammation in the lining (synovium) of joints, most often the joints of the hands and feet. The signs of inflammation can include pain, swelling, redness, and a feeling of warmth around affected joints. In some patients, chronic inflammation results in damage to the cartilage and bones in the joint. Serious damage can lead to permanent joint destruction, deformity, and disability.
When joints become inflamed due to RA, the synovium thickens and produces an excess of joint fluid. This overabundance of fluid, along with inflammatory chemicals released by the immune system, causes swelling and damage to the joint’s cartilage and bones.