Understanding Hernia - the Basics

What Is a Hernia?

A hernia occurs when an organ or fatty tissue squeezes through a hole or a weak spot in a surrounding muscle or connective tissue called fascia. The most common types 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 abdominal wall or into the inguinal canal in the groin. About 80% of all hernias are inguinal, and most occur in men because of a natural weakness in this area.

In an incisional hernia, the intestine pushes through the abdominal wall at the site of previous abdominal surgery. 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 afflicts 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 and two large blood vessels pass.

What Causes Hernias?

Ultimately, all hernias are caused by a combination of pressure and an opening or weakness of muscle or fascia: The pressure pushes an organ or tissue through the opening or weak spot. Sometimes the muscle weakness is present at birth; more often, it occurs later in life. Poor nutrition, smoking, and overexertion all can weaken muscles and make hernias more likely. Anything that causes an increase in pressure in the abdomen can then cause a hernia, including obesity, lifting heavy objects, diarrhea or constipation, or persistent coughing or sneezing.