Arthritis affects one in every seven Americans. It affects people of all ages. It most often begins as a person gets older.
Arthritis causes pain, stiffness, and swelling in or around joints.
These symptoms can develop suddenly or slowly. Only a doctor can tell if it's arthritis. The causes of most forms of arthritis are unknown, although we are learning more. People who are overweight have a higher chance of developing arthritis. Excess weight increases the risk for developing osteoarthritis in the knees.