Rheumatoid arthritis rheumatoid arthritis can cause pain swelling and deformity as the tissue that lines your joints synovial membrane becomes inflamed and thickened fluid builds up and joints erode and degrade rheumatoid arthritis is a chronic inflammatory disorder that can affect more than just your joints in some people the . Rheumatoid arthritis rheumatoid arthritis ra causes joint inflammation and pain it happens when the immune system doesnt work properly and attacks lining of the joints called the synovium the disease commonly affects the hands knees or ankles and usually the same joint on both sides of the body. Rheumatoid arthritis ra is an autoimmune disease that can cause joint pain and damage throughout your body the joint damage that ra causes usually happens on both sides of the body