Rheumatology is the specialty of medicine that includes arthritis and autoimmune diseases. Arthritis means inflammation of a joint. A joint is where two or more bones meet and move in relation to each other. They are separated by a rubbery substance called cartilage which is smooth and slippery, allowing for easy movement. Cartilage covers the end of each bone. Tendons and ligaments attach bones to muscles and other bones. Cartilage, tendons and ligaments are enclosed within a membrane around the joint which releases a fluid into the joint space to keep it well lubricated. Autoimmune disease is where an abnormality in the immune system leads to the body’s defence harming its own cells by mistake.