1.4.2 Umbilical hernia
Around 5 % of all hernias are umbilical hernias. Often, they are of a congenital nature and thus manifest already in infancy or at a young age. In adults mainly acquired hernias are seen, attributable – for example in pregnant women or persons engaging in heavy physical work – to increased internal abdominal pressure.
Since the tissue of the abdominal navel is, by nature, less stable than that of the surrounding tissues, the navel represents a natural weak point in the abdominal wall. In the umbilical hernia, the hernial sac protrudes through the umbilical ring; this is a ring-shaped opening in the tissue around the navel. The hernia manifests as a swelling in the navel region, and may be painful. The hernial sac may contain lymphatic or fat tissue from the abdominal cavity, and in some cases also parts of abdominal organs. Whereas strangulation is virtually never seen in congenital umbilical hernias, this is by all means possible in the case of acquired umbilical hernias occurring in adults. Therefore the latter cases should be operated on immediately. In most cases, a congenital umbilical hernia heals spontaneously, hence surgery is generally not needed.