The knee ringing downstairs can be physiological or pathological in origin. If there is a very slight ringing in the knee when going up and down stairs, like a popping sound, then this condition is generally physiological in nature, sometimes caused by a bubble sound, sometimes it is a popping sound along the track of the ligaments in the process of activity, and this condition can be treated without special treatment. If the ringing is accompanied by pain, pain in going up and down stairs, or the phenomenon of weak legs, walking and suddenly losing strength in the legs, it may be arthritis or meniscus damage, which requires attention, and try to go to the hospital for medical examination and imaging examination to confirm the diagnosis and treatment.