Here is a site explaining the difference. Click on:

http://osteoarthritis.about.com/od/o...01/a/OA_RA.htm

Osteoarthritis is also known as the wear and tear disease. Aging is one factor but it can happen earlier.

Rheumatoid Arthritis is an autoimmune disease and it is commonly known as the crippling disease. I'm not sure that it starts out being really stiff or not. I know it does make the hands, feet, etc. deformed.

Stenosis means narrowing and it can and does cause much pain. There is a link to it in my previous post.