An umbilical hernia in babies occurs when a small opening in the abdominal muscles allows part of the intestine or fatty tissue to bulge through near the belly button. It is common in newborns and infants, often appearing as a soft lump that becomes more noticeable when the baby cries or strains. Most umbilical hernias are painless and close on their own by age 3–5. However, in rare cases, if the hernia becomes trapped (incarcerated) and cannot be pushed back, medical intervention may be needed.