Knee joint squatting pain may be caused by physiological factors, such as poor blood circulation, etc., may also be due to pathological factors, such as meniscus injury, degenerative knee joint lesions. 1. Poor blood circulation: If you squat for a long time, it is possible that the blood flow in the knee is not smooth, resulting in a transient pain when squatting up. Avoid squatting action, appropriate massage and relaxation, the pain will generally reduce by itself. 2. Meniscus injury: when the lower limb activities, may lead to knee meniscus injury. If the meniscus degeneration or damage, when squatting, will cause irritation to the meniscus, thus squatting up the symptoms of pain. 3. Knee degenerative disease: it is a kind of degenerative knee arthritis caused by knee joint wear and degenerative damage of articular cartilage. When squatting and standing up, the cartilage in the knee joint produces friction, and the symptoms of joint pain and stiffness will appear. In addition to the above reasons, ligament injury, chondromalacia patella, rheumatoid arthritis, etc. may also lead to knee pain when squatting. If the pain in the knee joint cannot be relieved on its own, it is recommended to go to the hospital to further identify the cause of the pain and have targeted treatment.