There are more than 100 types of arthritis. Presently it affects more than 46 million U.S. adults. The number is expected to increase to 67 million adults by the year 2030.
There are two major types of arthritis: osteoarthritis ("wear and tear" arthritis), and rheumatoid arthritis, an inflammatory type of arthritis that happens when the body's immune system does not work properly.
Gout, is caused by crystals that collect in the joints, and is another common type of arthritis. Psoriatic arthritis, lupus, and septic arthritis are other types.
http://en.wikipedia.org/wiki/Arthritis
Importance of exercise in Arthritis
