Popliteal pain is the first symptom of knee osteoarthritis, meniscus injury and popliteal cyst. 1. Osteoarthritis of the knee: cartilage damage and osteophytes in the knee joint caused by aging, obesity and trauma will first cause popliteal pain, as well as joint swelling and limited movement. 2. Meniscus injury: meniscus injury caused by trauma or degenerative lesions can lead to popliteal pain behind the knee joint. 3. Popliteal cyst: caused by chronic aseptic inflammation or chronic knee joint lesions, etc. Activity can compress the cyst and popliteal pain occurs. Popliteal pain may also have other causes, should go to the regular hospital in time, by the doctor according to the symptoms, signs and auxiliary examination to determine the specific cause of the disease, for the cause of the correct treatment.