Double hydronephrosis should go to the hospital to find out the cause of hydronephrosis, the most common is urinary tract infection, especially when the urinary tract is heavily infected, it can cause double heavy hydronephrosis, combined with frequent urination, urinary urgency, painful urination, increased blood, bilateral lumbar pain, as well as chills, fever, malaise and other systemic discomforts. The diagnosis can be made clearly through routine urinalysis and other tests, and antibiotic treatment is needed for 10-14 days, and most of the fluid retention can be reduced or even disappeared after the infection is well controlled. Another common cause is urinary tract stones, such as bilateral ureteral stones, stones caused by ureteral obstruction can cause hydronephrosis, at this time can be ureteral lithotripsy treatment, usually first lithotripsy smaller side, and then lithotripsy more side. Another common cause is urinary tract occupation, such as urinary tract tumors or abdominal tumors caused by compression, if necessary, need surgical treatment.