Most of the pain areas on the lateral side of the knee are on both sides and medial side of the knee. The causes of pain on the lateral side of the knee may be related to goosefoot bursitis, meniscus injury, tendonitis and other factors, which should be analyzed reasonably according to different situations. 1. goosefoot bursitis: if the patient’s knee is sprained or there is arthritis of the knee joint, it will lead to the inflammation of the bursa of the suture muscle, thin femoral muscle, semitendinosus muscle and the medial side of the tibia bone, and the patient may have the pain on the medial side of the knee, and the patient can use the Futenurin ointment locally to reduce the pain, or take the drugs of Celecoxib capsules and Meloxicam tablets orally. 2. Meniscus injury: If the knee joint is traumatized or sprained due to weight bearing, and the pain site is on the inner and outer side of the knee joint, it may belong to meniscus injury or cyst, which can be examined by magnetic resonance imaging (MRI) and actively treated with surgery. 3. Tendonitis: If there is pain on the lateral side of the knee, it may be due to inflammation of the stopping point of the iliotibial bundle on the lateral side of the knee, due to the damage of the tendon fibrous tissue caused by the long-term frequent activities of the tendon, etc. It can be relieved by local icing, and it can be treated with medicines such as aspirin capsules and indomethacin tablets under the advice of a doctor. Therefore, when the side of the knee pain should go to the hospital in time, according to the specific conditions of the symptomatic treatment, to avoid more serious impact on daily life and the body. The use of medication should be in accordance with medical advice.