Edited by Dawnelle Nicholson Arthritis is a common term used for over 50 different joint diseases.
Inflammation includes redness, warmth, swelling and pain.
Osteoarthritis occurs when the cartilage in the joint wears out. The joint is surrounded by fluid to provide lubrication when the joint moves. With osteoarthritis, the cartilage breaks down allowing the bones to rub against one another. The ends of the bones thicken and pieces of bone break off and float in the joint space. As the cartilage is worn away, the nerves in the bones become irritated.