Arthritis is inflammation of a joint - the point where two or more bones meet.
There are more than 100 different diseases that are classified as arthritis - all of which may cause pain, swelling, and limited movement in joints and connective tissues in the body. 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.