Arthritis: Arthritis is a joint disorder featuring inflammation. A joint is an area of the body where two bones meet. A joint functions to allow movement of the body parts it connects. Arthritis literally means inflammation of one or more joints. Arthritis is frequently accompanied by joint pain. Joint pain is referred to as arthralgia. Arthritis is classified as one of the rheumatic diseases. These are conditions that are different individual illnesses, with differing features, treatments, complications, and prognosis. They are similar in that they have a tendency to affect the joints, muscles, ligaments, cartilage, and tendons, and many have the potential to affect internal body areas as well.