There are two different forms of arthritis that affect the body in different ways. Osteoarthritis and rheumatoid arthritis both cause damage to the joints, through the deterioration of the cartilage found on the ends of the bones where they meet in a joint. The damage to the cartilage caused by osteoarthritis is the result of wear-and-tear, either over the course of many years or due to an injury or infection to the joint. It also affects more than just the cartilage in the joint – the bone itself can change and the connective tissues that hold the joint together deteriorate. Rheumatoid arthritis on the other hand, is caused by an attack to the lining of the joint capsule, from the body’s own immune system. This attack will cause the lining, or synovial membrane, to become swollen and inflamed. Over time, the cartilage will be destroyed, as well as the bone that connects within the joint.