Joint movement can become more and more difficult when one or more parts of a joint are damaged from an injury, years of use, or a chronic disease. In most cases, cartilage, or the soft tissue layer that covers the ends of the bone at the joint, has cracked or worn away over time, causing stiffness and eventually pain.
The most common kinds of arthritis:
Osteoarthritis. Also known as degenerative arthritis, osteoarthritis is the most common type of arthritis and is caused by years of normal joint use. As you age, cartilage - the substance that cushions joints - breaks down and wears away, exposing bones and allowing them to rub together. Osteoarthritis is hereditary and is often seen in people who have abnormal joints, including knocked or bowed knees, or those who have had previous surgery.
Inflammatory Arthritis. Chronic diseases including rheumatoid arthritis and gout cause swelling and irritation in the joints, which causes the cartilage to break down. This type of arthritis can also be hereditary. Experts believe inflammatory arthritis is an autoimmune disease, or a rejection of the body's own tissues. Medication can control rheumatoid arthritis, but if the cartilage within the joint is destroyed, total joint replacement may be the only option to control the pain.
Post-Traumatic Arthritis. Injuries such as falls or car accidents can destroy cartilage and bone. If an injury does not heal properly, cartilage wears away over time, causing pain. The pain may be so severe that a person will avoid using the joint, weakening the muscles around the joint and making its movement even more difficult.