The word hernia comes from Latin, and means a rupture. The internal organs of the abdominal cavity are surrounded on all sides by a muscle layer of the abdominal wall. If pressure in the abdominal cavity increases, for example when you lift a heavy object, it is possible that part of the intestine breaks through the muscle layers. When this occurs, a so-called hernia sac protrudes outwards. It is often visible, or can be felt, as a lump under the skin.
Hernias can occur in various parts of the body. The most common types of hernia are inguinal (inner groin), incisional (resulting from an incision), femoral (outer groin), umbilical (belly button), and hiatal (upper stomach).
In an inguinal hernia, the intestine or the bladder protrudes through the lower abdominal wall or into the inguinal canal in the groin. About 96% of all groin hernias are inguinal, and most occur in men because of a natural weakness in this area. Two types of inguinal hernias are
• Indirect inguinal hernias, which are caused by a defect in the abdominal wall that is congenital, or present at birth
• Direct inguinal hernias, which usually occur only in male adults and are caused by a weakness in the muscles of the abdominal wall that develops over time
A ventral hernia is a bulge of tissues through an opening of weakness within your abdominal wall muscles. It can occur at any location on your abdominal wall. Many are called incisional hernias because they form at the healed site of past surgical incisions. This type is most common in elderly or overweight people who are inactive after abdominal surgery.
A femoral hernia occurs when the intestine enters the canal carrying the femoral artery into the upper thigh. Femoral hernias are most common in women, especially those who are pregnant or obese.
In an umbilical hernia, part of the small intestine passes through the abdominal wall near the navel. Common in newborns, it also commonly afflects obese women or those who have had many children.
A hiatal hernia happens when the upper stomach squeezes through the hiatus, an opening in the diaphragm through which the esophagus passes.