Severe hydronephrosis in the elderly requires further comprehensive examination and evaluation at the hospital to clarify the cause and then treat it symptomatically. 1. If the GFR of kidney function is less than 10% and the examination later is benign disease causing hydronephrosis, the hydronephrosis can be considered at this time to remove the kidney to achieve the purpose of cure. However, for elderly patients with life expectancy less than 5 years, any treatment is not recommended, as long as there are no symptoms regular clinical observation and review can be done, otherwise surgery can increase certain risks and lead to further decrease in life expectancy. 2. If it is a malignant disease causing severe hydronephrosis, such as renal tumor, ureteral tumor, etc., it is recommended to take surgical treatment as much as possible after detailed evaluation, if there is an opportunity for surgery Radical surgery can prolong the survival of the patient after removal. However, if the severe hydronephrosis has combined with metastasis of other organs, you can choose radiotherapy and chemotherapy according to the patient’s specific physical condition. 3. If the hydronephrosis is caused by benign disease and you are not willing to accept surgery, you can perform ureteral stent tube drainage or kidney puncture drainage, and then dynamically observe the changes of hydronephrosis after drainage.