Hydronephrosis accompanied by pain is generally caused by kidney stones lodged in the ureter leading to renal colic, and the stones in the ureter can cause urinary obstruction, thus presenting as hydronephrosis.

To alleviate the pain in such cases, treatment methods are chosen based on the size of the stone. If the kidney stone is relatively small and estimated to be able to pass by itself into the bladder, temporary use of pain relief medication can be administered for symptomatic treatment, along with medication that dilates the ureter to expand its diameter, facilitating the expulsion of the stone.

If the stone is large and predicted not to pass on its own, temporary symptomatic treatment with pain relief medication can be used. Meanwhile, after completing preoperative examinations, surgery can be performed to remove the stone, which can also completely alleviate the pain symptoms.