Approximately 40 million people in the United States have arthritis. It is a disorder of the joints that connect the bones of the body. The name arthritis means joint inflammation or swelling. Joints are located wherever two or more bones meet. Cartilage and a lubricating fluid form a smooth gliding surface for the bones of the joint. Ligaments hold the joint together. When joints become injured or diseased, they swell. Over 100 types of arthritis affect the joints and connective tissues of the body.