Heavy fluid retention in the kidney may damage the renal tubules or lead to the emergence of uremia, which needs to be dealt with promptly according to the cause. The common causes of severe hydronephrosis kidney stones, ureteral stenosis, tumors and so on. If the treatment is not timely, the severe hydronephrosis may affect the function of the kidney, and the renal tubules may be damaged, and the obstruction should be removed in time according to different causes to protect the renal function. Severe hydronephrosis can be relieved by urine drainage, which in turn protects the kidneys. For patients who already have a large amount of hydronephrosis and cannot get rid of the obstruction immediately, a urinary drainage route should be established in time to fully drain the urine to relieve the symptoms of obstruction. If patients have severe hydronephrosis, they should go to the hospital in time and be treated under the guidance of specialists.