Bilateral X-ray of the hands and wrists of a 54 year old patient with rheumatoid arthritis. On the right hand (left), there is arthritis in the wrist joints. There is a loss of bone space and the bones are beginning to fuse. On the left hand (right), there are bony growths in the left finger joints causing inflammation. Rheumatoid arthritis is a degenerative autoimmune disease that mainly affects the capsule (synovium) around the synovial (flexible) joints, causing chronic inflammation. It can be a debilitating and painful condition and can lead to deformities and loss of functioning and mobility.