Hello! Hydronephrosis is dilatation of renal pelvis due to obstruction to urine outflow. Cause of obstruction needs to be diagnosed. In my clinic, I advise ultrasound abdomen, X-ray KUBU, renal function tests. You havent mentioned about fever. Local examination of testes & abdomen is important. Hope this information is useful to you. Feel free to ask any further query with reference to your reports & progress. Regards.