Arthritis causes joint pain primarily due to inflammation and damage to the joints. In Osteoarthritis, the protective cartilage that cushions the ends of bones gradually wears down, leading to bone-on-bone contact and resulting in pain, stiffness and swelling. Rheumatoid Arthritis, an autoimmune condition, triggers inflammation that affects the synovium, the lining of the joints. This inflammation can lead to joint pain, swelling and stiffness. In both types of Arthritis, the ongoing inflammation and structural changes in the joints contribute to the persistent pain experienced by individuals with Arthritis. Pain can vary in intensity and may be exacerbated by movement or weight-bearing activities.