Final answer:
Osteoarthritis is caused by aging and wear on joints, while rheumatoid arthritis is an autoimmune disease leading to inflammation and pain in the joints.
Step-by-step explanation:
The causes of common forms of arthritis include the effects of aging and autoimmune diseases. Osteoarthritis is associated with aging and "wear and tear" on the articular cartilage. Factors contributing to osteoarthritis may include injury, physical labor, certain sports, and being overweight, leading to stress on the joints and eventual thinning of the cartilage. Over time, this can result in pain, stiffness, and decreased mobility of the affected joints. In contrast, Rheumatoid arthritis (RA) is an autoimmune disease where the body's immune system mistakenly attacks healthy tissues inside the joints. RA leads to inflammation, pain, and joint damage and can affect various joints in the body. While osteoarthritis is related to mechanical stress and insufficient self-repair of cartilage, RA involves a chronic inflammatory response, influenced by both environmental and genetic factors.