Arthritis Basics

The word "arthritis" literally means joint inflammation ("arthr-" means joint; "-itis" means inflammation). It refers to more than 100 different diseases. These diseases usually affect the area in or around joints, such as muscles and tendons. Some of these diseases can also affect other parts of the body, including the skin and internal organs. Arthritis usually causes stiffness, pain and fatigue.

Over 43 million Americans, or one in every seven people, have arthritis, according to the Arthritis Foundation. It affects people of all ages, but it most often comes on as a person gets older.

The articles in this section offer information about the basics of arthritis and the main support groups for people with arthritis.