Hydrocele is a relatively common disease in pediatric urology, and I would like to talk about a few questions that are often asked by patients at work, hoping that they will be helpful. 1, prenatal discovery of fetal hydronephrosis to terminate pregnancy: this is a more difficult problem, my work experience is: most of the fetal hydronephrosis is physiological hydronephrosis, usually at birth or 1 year after birth can disappear on their own, these children do not need treatment. Pathological hydronephrosis, such patients are divided into several cases: first, the most common one is obstruction of the pelvic ureteral junction. The treatment of this disease is ideal and the child’s quality of life is not reduced, so abortion is also not recommended. Secondly, for double kidney dysplasia, polycystic kidney and some serious lower urinary tract obstruction, it is necessary to judge whether to terminate the pregnancy according to the specific situation and examination. At this time, parents are reminded to pay more attention to the amount of amniotic fluid, which is significantly reduced as a danger signal that the fetus is suffering from urinary tract disease. 2, which hydronephrosis need surgery: it is generally believed that after birth ultrasonography, the renal pelvis separation greater than 20mm, through follow-up, the gradual increase in hydronephrosis, and do intravenous pyelogram (IVP), renal chart (ECT) renal function decline, the need for surgical treatment. At this time, parents should be reminded that if the fetus is prenatally found to have hydronephrosis, it must be examined by a professional pediatric urology department after birth, and regular follow-up should be done to observe the changes of hydronephrosis to avoid further damage to the kidney. 3.When to do surgery: Nowadays, medicine has made great progress than before, especially the application of pediatric anesthesia and minimally invasive technology, which has expanded the scope of surgery for surgeons. Hydronephrosis can be treated surgically from newborn, but because some physiological hydronephrosis is possible, most of our hospitals follow up and observe until about 10 months to 1 year old, and surgery is needed if there is no improvement. During the observation period, if the hydronephrosis increases significantly, the surgery should be performed earlier. 4.How to operate: This is actually a subject for doctors. Parents need to know that, first, pediatric surgery requires general anesthesia. Second, surgery for pediatric hydronephrosis is a very delicate surgical operation. Third, common hydronephrosis, such as pelvic ureteral junction stenosis (PUJO), is mostly treated with disconnected pyeloplasty. The treatment effect is better. 5.Treatment effect: For common ones such as PUJO and uretero-vesical junction obstruction, the treatment effect is satisfactory, with high success rate and normal quality of life of the child after the disease is cured. There are many parents always ask me a question, whether the kidney is completely free of fluid after hydrocele surgery. Here I have to talk about what is the purpose of the surgery, I think it is to prevent further damage to the kidney. That means some of the kidney damage before the surgery is already irreversible, the kidney function may improve after the surgery, but the fluid will still be there, as long as it doesn’t continue to worsen, the surgery is successful. Otherwise, if the child does not have surgery, the kidney damage will continue to increase, and many of them may have to have nephrectomy when they reach adulthood. So this point needs to be understood by parents.