In arthritis, inflammation occurs in the damaged area of a joint. Damage may be caused by any number of conditions, including trauma, infection, neurogenic disturbances, degenerative joint disease, metabolic disturbances, or for unknown reasons. Symptoms of inflammation include redness and warmth in the area of the injury, swelling, and pain. Arthritis is usually chronic, which means that it rarely changes, or it progresses slowly. Specific causes for most forms of arthritis are not yet known.
Cartilage is made up of cells and fibers and is found mostly in joints.
It is a chronic disease involving the joints, particularly the weight-bearing joints such as the knee, hip, and spine. It occurs in most people as they age, but also may occur in young people as a result of injury or overuse. The inflammation often affects the joints of the hands and the feet and tends to occur equally on both sides of the body. It can usually be controlled with medication and changes in diet. Learn more about arthritis treatment .