Arthritis literally means “inflammation of a joint.” In some forms of arthritis, such as osteoarthritis, the inflammation arises because the smooth covering (articular cartilage) on the ends of bones become damaged or worn. Osteoarthritis is usually found in one, usually weightbearing, joint.
In other forms of arthritis, such as rheumatoid arthritis, the joint lining becomes inflamed as part of a disease process that affects the entire body. Some other types of arthritis are: seronegative spondyloarthropathies, crytalline deposition diseases, and septic arthritis.
Arthritis is a major cause of lost work time and serious disability for many people. Although arthritis is mainly a disease of adults, children may also have it.