There are actually three common types of arthritis. These are
Osteoarthritis which is the most common, affecting around 16
million Americans with an average age of 45. It usually will
attack weight bearing joints like knees, hips, and ankles but has
been found in the fingers, neck and spine. Each of our joints
is cushioned by cartilage, a very dense, sponge-like substance.
Osteoarthritis attacks that cartilage and gradually wears it
down.Another type of arthritis is Rheumatoid Arthritis. Extrem.