Umbilical hernia

Definition:

A protrusion of a portion of abdominal organ(s) through the umbilical ring, which is the muscle tissue around the navel (belly-button).

Causes, incidence, and risk factors:

An umbilical hernia in an infant is caused by the incomplete closure of the umbilical ring (muscle), through which the umbilical blood vessels passed to provide nourishment to the developing fetus. The hernia is noticed as a soft swelling beneath the skin that often protrudes with crying or straining. Depending on the severity, the area varies in size from 1 to 5 centimeters in diameter. Small hernias usually close without treatment by age 1 or 2. Umbilical hernias are usually painless. Umbilical hernias occur slightly more frequently in infants of African American descent.