In clinical practice, hydronephrosis is mostly caused by urinary tract obstruction due to urinary stones and other diseases, resulting in urine retention and thus inducing obstructive renal pathology. Some young patients with hydronephrosis may not have any signs or abnormalities in the early stages of the disease, and often do not experience any discomfort until they are in their teens, such as distension and pain in the kidney area, oliguria, or even anuria. The clinical symptoms of hydronephrosis caused by prolonged obstruction are relatively more numerous, such as back pain, lumps in the lower abdomen with hematuria, oliguria, or even anuria. A small number of patients may also have gastrointestinal symptoms, and when secondary infection occurs, there will also be an increase in body temperature, if not treated in time, it may induce kidney function damage, or even kidney failure. The occurrence of hydronephrosis is closely related to people’s dietary habits, and people with a single diet and who often sleep late are prone to hydronephrosis. It is also important to note that during pregnancy, women may also have mild hydronephrosis of the kidneys and ureters, which is directly related to the increase in the size of the fetus and compression of local tissues, and can cause edema in the feet of pregnant women. Since the causes of hydronephrosis are particularly numerous, once patients are found to be possibly suffering from hydronephrosis disease, they should be checked for urine protein and urinary system examination, and then treated symptomatically. In summary, hydronephrosis is an obstructive nephropathy caused by urinary tract obstruction, and most of them need active disposal and, if necessary, surgical treatment.