Arthritis is a general term that describes inflammation in joints.
Osteoarthritis, also called degenerative joint disease, is the most common type of arthritis. It is associated with a breakdown of cartilage in joints and commonly occurs in the hips, knees, and spine. Also, it often affects the finger joints, the joint at the base of the thumb, and the joint at the base of the big toe. Cartilage is a firm, rubbery material that covers the ends of bones in normal joints. The shock-absorbing quality of normal cartilage comes from its ability to change shape when compressed.