Arthritis at a Glance Arthritis is Arthritis is a chronic disease that includes over 100 different conditions characterized by joint pain, stiffness and sometimes swelling.
Arthritis causes pain, stiffness, a decrease in mobility, and activity limitations.
The joint cartilage, underlying bone and supporting tissue may undergo degenerative changes. It affects 21 million Americans. Fibromyalgia is a pain syndrome involving muscles and muscle attachment areas. It affects 3.7 million Americans. Rheumatoid arthritis is an inflammation of the joint lining.