Question: what is the difference between osteoarthritis (oa) and rheumatoid arthritis (ra)?
Answer: The main difference between osteoarthritis and rheumatoid arthritis is the cause behind the joint symptoms. Osteoarthritis is caused by mechanical wear and tear on joints. Rheumatoid arthritis is an autoimmune disease in which the body's own immune system attacks the body's joints. It may begin any time in life.