Hydronephrosis in children has the following main effects on children’s health: 1. In the early stage of hydronephrosis, children often have no obvious symptoms, and occasionally have lumbago and back pain.2. With the gradual aggravation of the degree of hydronephrosis, the child may have symptoms of urinary tract infection such as frequent urination, urinary urgency, urinary pain, and even difficulty in urination, and poor urinary flow.3. If the hydronephrosis does not get effective treatment further aggravates, then there will be high blood pressure, little urine, or even no urine, kidney function is seriously impaired, and some of them will have the symptoms of uremia.