Hydronephrosis is actually “nephrolithiasis”, which is a manifestation of urinary tract irregularities caused by various reasons. Ignoring it may delay the treatment of the original disease and cause the kidney to lose its function, leading to serious consequences. So what should I do if I find hydronephrosis? It is crucial to find a specialist for further diagnosis and treatment. First of all, it is necessary to determine whether it is hydronephrosis. Many patients have hydronephrosis detected by ultrasound, and ultrasound diagnosis of hydronephrosis can sometimes be misdiagnosed, for example, parapelvic cysts or pot-bellied pelvis are diagnosed as hydronephrosis. Therefore, specialists usually recommend urography to determine hydronephrosis and its site of obstruction. Once the hydronephrosis is identified, further work is done to find the cause of the hydronephrosis and to assess the function of the affected kidney. The treatment of hydronephrosis is divided into two aspects. First, the primary cause of hydronephrosis should be treated as much as possible to unblock the urinary tract, relieve hydronephrosis and protect kidney function. For example, hydronephrosis caused by ureteral stones is relieved by removing the stones. Sometimes it is necessary to remove the affected kidney, for example, malignant tumor causing hydronephrosis, pus accumulation in the affected kidney and non-functioning of the affected kidney. For patients whose primary disease cannot be managed or temporarily cannot be managed, placement of ureteral stent tubes or nephrostomy on the affected side can be considered from the perspective of protecting renal function.