Hello,
Arthritis means joint inflammation. Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints. Rheumatoid arthritis can also cause inflammation of the tissue around the joints, as well as in other organs in the body.
Osteoarthritis is a type of arthritis that is caused by the breakdown and eventual loss of the cartilage of one or more joints. Cartilage is a protein substance that serves as a "cushion" between the bones of the joints. Osteoarthritis is also known as degenerative arthritis.Cause of osteorthritis is unknown.
Pathphysiology of both is different.also mode of treatment for both is different.Moreover any relationship between the two has not been proved.
Hope it helps.Take care and pls do keep me posted if you have any additional queries.
n interersting question. I have a theory, developed because a friend has Hep C and developed severe arthritis after two years of "immune enhancers" from a Chinese non-licensed physician. Immune enhancing substances often work by acting as antigens, provoking a non-self respone - i.e. an inflammatory response. While these treatments may be helpful in combating hep c, they can cause joint inflammation.