39 years old, both knees are sore when going up and down stairs, the most common causes are osteoarthritis of the knee joint and meniscus injury, which can be given conservative and surgical treatments. 1. Osteoarthritis of the knee: Knee pain can be aggravated during activities, especially when going up and down stairs. Physical therapy, medication (non-steroidal anti-inflammatory drugs such as aspirin and ibuprofen; bone protectors such as hyaluronic acid and D-glucosamine), and surgery (arthroscopic knee cleanup, artificial joint replacement) can be given. 2. Meniscus injury: according to the degree of injury, conservative treatment such as knee joint braking and resting, meniscus repair and other surgical treatments can be given. There may be other reasons for the pain of going up and down the stairs of both knees, and it is recommended to consult a doctor to improve the examination and clarify the cause of the disease, and then give targeted treatment or treatment, and not self-medication.