A bulging belly button in an infant is considered an umbilical hernia in medical diagnosis. This is because the umbilicus and abdominal wall are not well developed and relatively weak during the congenital development of infants. Therefore, when an infant cries vigorously for a long time or has poor digestion, increased gas accumulation in the gastrointestinal tract and increased pressure in the abdominal cavity, it can easily lead to umbilical bulge and form an umbilical hernia. Umbilical hernia does not require special treatment, as long as care is taken to avoid prolonged violent crying and actively prevent and treat digestive diseases. More than 80% of umbilical hernias will gradually shrink and even close naturally as they grow older and develop physically. A small number of infants still have obvious umbilical hernia when they are older than 2 years old, or the diameter of umbilical hernia is larger than 2 cm and it is difficult to heal naturally before surgical treatment is needed.