Osteoarthritis often occurs due to the degeneration associated with aging, causing damage to the essential cartilage, leading to symptoms such as joint pain and deformities during movement. In the case of osteoarthritis, it is crucial to keep warm and rest, avoid exposure to cold, and minimize knee-joint load-bearing activities such as mountain climbing and stair climbing. Instead, choosing activities like Tai Chi and swimming, which cause less joint wear, can help alleviate symptoms and prevent accelerated cartilage damage.