A spherical soft sac protruding from the umbilicus in infants is an umbilical hernia, which in my personal experience is more common in preterm infants than in term infants. An umbilical hernia is a bulging of the intestinal tube from the umbilicus into the skin, forming a spherical soft sac that can be easily recovered by finger pressure. Umbilical hernia occurs because the rectus abdominis muscle on both sides of the umbilicus does not close at the umbilicus after the umbilical cord is detached from the baby, leaving a defect. Various causes of increased pressure in the abdominal cavity, such as coughing, diarrhea, excessive crying, etc. can contribute to the occurrence of umbilical hernia, the hernia sac for the protrusion of the peritoneum and skin, protruding viscera are mostly small intestine, umbilical hernia is rarely incarcerated, unlike inguinal hernias, there is no incarcerated risk of intestinal obstruction. Umbilical hernia in crying, coughing, increase in size, with light pressure can make the hernia content into the abdominal cavity, and can be heard over the sound of gas. The size of umbilical hernia is between 1~3cm, most of them do not have any discomfort, most of them grow back within 1 year, and a few of them heal within 2 years of age. There is no need to use a coin or piece of wood slightly larger than the umbilical hernia, wrapped in gauze and pressed on the umbilical hernia, because this method is ineffective, but can cause skin breakage to the point of penetration, there is a risk that the intestinal tube will be damaged.