Signs of pediatric moderate hydronephrosis usually include vague pain, soreness and swelling in the lower back and abdomen, but the severity of hydronephrosis cannot be judged by clinical symptoms alone. The main symptom of pediatric moderate hydronephrosis is pain in the lower back and abdomen, which can be divided into vague pain and soreness, and may be accompanied by swelling in the lower back and abdomen, which is often more obvious during activities and gradually aggravated with the development of the disease, but there are still a small number of patients who may not have any clinical symptom, so it is not possible to judge the severity of hydronephrosis only by the clinical symptoms. When suffering from hydronephrosis, patients should undergo regular checkups, such as urological ultrasound examination, which can accurately assess the severity of hydronephrosis in clinical practice.