The most common type of arthritis is osteoarthritis. Also known as "wear and tear" arthritis, osteoarthritis occurs when the cartilage that cushions and protects the ends of your bones gradually wears away. It results from overuse, trauma, or the natural degeneration of cartilage that occurs with aging. Osteoarthritis is often more painful in joints that bear weight, such as the knee, hip, and spine. However, joints that are used extensively in work or sports, or joints that have been damaged by injury may show signs of osteoarthritis.