Osteoarthritis is the most common form of arthritis that involves the breakdown and eventual loss of cartilage in one or more joints. It occurs when the protective cartilage on the ends of bones wears down over time. Common symptoms include joint pain, stiffness, and limitation of movement, especially in weight-bearing joints like the hips and knees. While there is no cure for osteoarthritis, treatments can help reduce pain and maintain joint movement, including medications, physical therapy, exercise, and sometimes surgery. Osteoarthritis is diagnosed based on a patient's medical history and symptoms as well as physical examination and imaging tests.