What Causes Umbilical Hernia?

Umbilical hernia is an external abdominal hernia in which intra-abdominal contents protrude through a weak area at the umbilicus. In infants with umbilical hernia, a bulge—typically hemispherical or sac-like—appears at the navel. Several factors contribute to its development. Normally, after the umbilical cord is clamped and severed at birth, it gradually dries up and falls off over time. However, during fetal development, the umbilical cord passes through the abdominal wall, leaving behind a naturally weaker region at the umbilical scar. At birth, the two rectus abdominis muscles have not yet fully fused along the midline, resulting in a residual gap. When intra-abdominal pressure increases, abdominal contents may thus protrude outward through this defect, leading to umbilical hernia.

Secondly, infants undergo rapid physical growth and development after birth. During feeding, infants often swallow air, which may cause choking or coughing. Crying further exacerbates abdominal distension and elevates intra-abdominal pressure. Because newborns have underdeveloped abdominal musculature and poor contraction of the umbilical ring, increased pressure can push the small intestine—along with the peritoneum and overlying abdominal skin—outward through the umbilical defect, resulting in umbilical hernia.

Prompt treatment is essential following diagnosis of umbilical hernia. In many cases, the condition improves spontaneously as the child grows older; however, progression or complications may occur, necessitating close monitoring and appropriate medical intervention.