The baby did not urinate at night may be caused by physiological factors such as low water intake, overheated environment, or may be caused by diseases such as glomerulonephritis and nephrotic syndrome. 1. Physiological factors: if the child drink less water during the day may lead to less water in the child’s body, not enough to urinate. In addition, it may be caused by the high temperature of the environment or sleeping under too thick a blanket and wearing more clothes, etc. The child will sweat a lot, and the water in the body will evaporate, so the baby will appear a night without urine. 2. Glomerulonephritis: the child will have hematuria, edema, anuria, oliguria and other symptoms, so the baby will have the symptom of no urine at night. 3. Nephrotic syndrome: the main symptoms of patients are proteinuria, edema, etc. Nephrotic syndrome will lead to poor kidney metabolic function of the child. As a result, the affected baby will have the performance of no urine at night. When the baby will have the symptom of no urine at night, it may be caused by physiological factors and no treatment is needed. If it is caused by disease, parents should take their children to the doctor in time.