What are the symptoms of bilateral hydronephrosis?

The symptoms of bilateral hydronephrosis include dull pain in the bilateral renal areas. In mild cases, hydronephrosis usually presents no obvious symptoms; however, back or flank pain may occur when the condition becomes severe. If hydronephrosis is complicated by infection, symptoms such as flank pain, abdominal pain, frequent urination, urgency, dysuria, and fever may appear. If the condition continues to worsen, it is highly likely to impair kidney function, leading to decreased renal function and elevated levels of blood urea nitrogen and creatinine.