The ringing inside the knee may be a sign of meniscus injury, chronic osteoarthritis or chronic synovitis. 1. Meniscus injury: meniscus is the cartilage tissue in the knee, cartilage injury after strenuous exercise will lead to wear and tear of the cartilage, and there will be internal noise when the knee is active. 2. Chronic osteoarthritis: after chronic osteoarthritis occurs, the fascia, cartilage and other connective tissues in the knee may have pathological changes such as hyperplasia and sclerosis, and the joints will become stiff, and there will be the performance of zigzagging inside the knee. 3. Chronic synovitis: synovial tissue inflammatory lesions, there will be local congestion and edema, will also appear inside the knee ZiZi ringing situation, but also accompanied by knee pain symptoms. The knee is usually seen in a variety of diseases, the need for appropriate rest and avoid excessive stress on the knee, to rule out physiological reasons, we recommend timely consultation targeted treatment and treatment.