Rheumatoid arthritis (RA), an autoimmune disease, can cause osteoarthritis (OA). RA occurs when the immune system mistakenly attacks the joints causing pain and stiffness, as well as muscle pain, fatigue, weight loss and flu-like symptoms.
The most common causes of OA are age-related wear and tear, obesity and injuries. But OA can also be caused by medical conditions such as rheumatoid arthritis too. Damage caused to the joints by RA can wear down cartilage, causing the bones to rub, which often results in osteoarthritis.