There are many diseases that cause tendon pain below the knee, the common diseases are the following: 1, patellar tendonitis: due to long-term chronic strain, can lead to aseptic inflammation of the patellar tendon located at the tibial stop, there will be symptoms of pain below the knee. In this case, you should reduce the activities of the knee joint, pay attention to rest, but also need to pay attention to warmth, to prevent the knee from getting cold, pain can be oral non-steroidal anti-inflammatory drugs anti-inflammatory analgesic treatment, but also oral or external use of blood stasis Chinese medicine, such as oral Pan Long Qi tablets or external use of blood pain cream, but also with local physiotherapy, such as shock wave therapy, for pain relief also has a very good effect. 2. Injuries to the cruciate ligament or meniscus within the knee joint can also cause pain in the tendons below the knee. If you have pain below the knee, you need to go to the hospital and get an MRI of the knee to see if there is any damage to the cruciate ligament or meniscus. If there is damage, conservative treatment or minimally invasive arthroscopic surgery will be required depending on the damage.