Whether severe hydronephrosis can survive for a long time depends on the actual condition of the patient. Because the human body has two kidneys, if it is a unilateral severe hydronephrosis, usually one side of the kidney function will be lost, but the other side of the kidney function can completely compensate for the metabolism in the body, so it will not affect the life of the patient. The fluid in the nephrotoxic kidney, which causes the loss of kidney function, can be removed from the fluid-bearing kidney, and there is one kidney that can completely compensate for the function of both kidneys. Therefore, even if one side of the kidney has severe hydronephrosis, resulting in loss of kidney function, it can still survive for a long time. In case of bilateral severe hydronephrosis, the patient is usually in a serious condition, at which time the kidney function is completely lost and the life can be prolonged by the treatment of dialysis.