Tendon pain in the hamstring behind the running knee can be treated with general treatment, physical therapy, medication and surgery depending on the cause. It may be caused by tendonitis, tendon strain, meniscus injury, lumbar disc herniation and so on. 1. Tendonitis: If the tendons and local tissues have aseptic inflammation, it will cause tendon pain at the back of the knee, you can take non-steroidal anti-inflammatory drugs, such as celecoxib, etc., to alleviate the inflammation and reduce the pain. Physical therapy such as hot compresses and ultrasound can also be performed. 2. Tendon strain: If there has been excessive exercise, it may cause tendon strain, resulting in tendon pain. If the injury is not serious, you can use safflower oil to apply on the affected area, or use non-steroidal anti-inflammatory drugs such as celecoxib for pain relief. 3. Meniscus injury: The loss of meniscus may be caused by excessive weight bearing while running. If the injury is one or two degrees, conservative treatment is sufficient; if it is a third degree meniscus tear, arthroscopic meniscus closure is required. 4. Lumbar disc herniation: Lumbar disc herniation may have the symptom of compression of lumbar spinal nerve, causing radiating pain and numbness in the lower limbs. You should pay attention to rest and take painkillers such as ibuprofen and nerve-nourishing drugs such as methylcobalamin orally. Physical therapy such as lumbar traction and acupuncture can also be performed under professional guidance. Minimally invasive nucleus pulposus removal surgery can be considered if conservative treatment is ineffective. There are other causes of running behind the knee hamstring pain, such as osteoarthritis, lower extremity vascular disease, etc., if the symptoms continue to be unrelieved, it is recommended to consult a doctor in a timely manner, improve the examination to determine the cause of the disease, and comply with the doctor’s instructions for specific treatment, do not use their own medication.