An umbilical hernia is a navel that bulges with crying or straining. The bulge may disappear when your baby is quiet. If you feel the area with your finger, you will find a small round opening in the muscles of the abdominal wall. The hernia passes through this ring.
Umbilical hernias are very common.
Crying does not make them any bigger or last any longer. They are not painful and they never break. The opening in the muscles usually closes spontaneously by school age. Half of the persistent ones close by adolescence. No treatment is needed unless the hernia persists beyond the age of 5 or 6 years.