Umbilical hernia

An umbilical hernia refers to the protrusion of a small amount of abdominal organs (mostly small intestine) through the umbilical ring when intra-abdominal pressure increases, forming a round or oval bulge at the umbilicus. Umbilical hernias generally include three types: fetal umbilical hernia, infantile umbilical hernia, and adult umbilical hernia. The incidence of umbilical hernia is higher in infants, especially premature and low-birth-weight infants. The incidence gradually decreases with age, presenting as a soft bulge or protrusion at the umbilicus.