A belly button hernia, more properly known as an umbilical hernia, is a type of abdominal hernia which occurs in the region of the navel. When this type of hernia develops, the intestines push through the abdominal wall behind the belly button, causing a characteristic bulge to appear. Many belly button hernias are congenital in nature, and they are especially common in boys of African descent. This type of hernia can also be acquired by adults.

The navel region is vulnerable to herniation in infants because of the way in which the body develops, and because of the nature of the umbilicus. In some cases, the abdominal wall behind the navel fails to close completely during fetal development, allowing intestines to push through and create a hernia. The belly button hernia may only be visible when an infant cries or strains, subsiding back into the abdomen when the baby relaxes. It is usually identified shortly after birth, since newborn infants tend to strenuously object to being pushed out into the world, making their belly button hernias rather prominent.

Unlike other hernia types, a belly button hernia often resolves itself. In infants, the hernia may disappear by age one, and definitely by age four in most cases. If the belly button hernia continues to be present after this point, it may require surgical correction. The hernia is also prone to complications such as strangulation, in which the blood supply to the herniated intestines is cut off, causing tissue death. If a baby has a belly button hernia, a doctor may recommend close monitoring for the early signs of a problem.

In adults, a belly button hernia appears as a result of strain. As in infants, the hernia presents as a lump behind the navel which causes a bulge which may vary in size depending on the position of the patient and whether or not the patient is straining or tensing. In adults, this hernia should be corrected surgically to avoid the possibility of complications.

For those who feel like throwing around some medical terminology, the belly button hernia is also known as an “exomphalos,” literally “out navel,” in a reference to the fact that the navel pushes out from the body as a result of the herniation. A belly button hernia should not be confused with an “outie” belly button, a perfectly normal physical feature. A herniated navel will protrude much more than an outie belly button, and it may be accompanied by pain and soreness, especially in adults.