How does an umbilical hernia develop?
Umbilical hernias form because of a weak area in the muscles of your belly. The cause of this weakness differs between children and adults.
Before birth, a baby’s stomach muscles have a small opening for the umbilical cord to pass through. After birth, the muscles gradually close. An umbilical hernia can form before the muscles have closed or if the muscles don’t completely join.
In adults, abdominal pressure can cause a weakness in your muscles. This can be due to obesity, giving birth multiple times, abdominal surgery, or fluid buildup in the stomach (ascites). Umbilical hernias are more common in people who are assigned female at birth.