What is the rheumatoid arthritis medical definition?

[KeithD]

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation of the joints and surrounding tissues, leading to pain, stiffness, swelling, and ultimately, joint damage and deformity. It occurs when the body's immune system attacks its own tissues, particularly the synovium (the lining of joints). This leads to chronic inflammation and can affect not only the joints but also other organs, such as the skin, eyes, lungs, and blood vessels.