Knee ringing may be physiological ringing, or it may be caused by meniscus injury, osteoarthritis, bursitis and other pathological reasons. 1. Physiological popping: knee popping may be physiological popping, usually only sound, will not lead to joint pain, soreness or activity limitation, mainly is the friction between the articular cartilage and synovial membrane and the movement produces sound, is a normal phenomenon. 2. Meniscus injury: half-flexion, adduction or abduction of the knee, gravity compression and rotation force on the knee joint activities, resulting in meniscus rupture, resulting in knee rattling, mainly manifested in severe pain, inability to straighten the knee joint, swelling and other symptoms. 3. Osteoarthritis: knee ringing may be caused by osteoarthritis, usually associated with genetic, weight bearing, metabolic inflammatory factors, mainly manifested as joint friction pain and crunching sound, and occasionally joint interlocking. 4. Bursitis: If the bursa is damaged, long-term friction and compression, resulting in aseptic inflammation of the bursa, which leads to the ringing of the knee. In addition, the iliotibial bundle tension, intra-articular free body can also lead to knee ringing, if accompanied by obvious symptoms, we recommend that you go to the hospital in a timely manner, improve the relevant examination, clear the cause of the disease, and then follow the doctor’s instructions to take targeted treatment, so as to avoid delaying the condition.