Three weeks after taking a part-time job hauling furniture, Rick noticed a small protrusion of tissue near his groin. He went to see his physician, who diagnosed the problem as an inguinal hernia.

"A hernia is a gap in the tissue layers that line the abdominal wall. When those tissues weaken through overexertion or repeated strain, a piece of intestine or other intra-abdominal tissue can begin to bulge out through the gap," says Kim Ephgrave, MD, professor of surgery at the University of Iowa College of Medicine and chief of general surgery at the Veterans Affairs Medical Center in Iowa City.

"Straining, heavy lifting, and heavy labor are the most common causes, but any repetitive strain, including obesity, multiple pregnancies, or even a smoker's cough may contribute to development of a hernia," she says.

Men are five times more likely than women to develop inguinal hernias, which are hernias in the groin and the most common. An umbilical hernia, which occurs near a newborn's belly button, is the second most common. The other common type is an incisional hernia, which occurs after surgery. In most cases, surgery is indicated to repair the bulge and prevent intra-abdominal tissue from being trapped outside.

Repair of hernias is accomplished by dissecting free and then pushing back the protruding tissue, then tightening the loose tissues with stitches. Often, a piece of synthetic material is sewn into place to help hold in the protruding tissue.

When the protruding tissue contains a length of intestine, two secondary problems can result. One risk is that the hernia will cause an obstruction of the intestines, resulting in pain, nausea, and vomiting. A second risk is strangulation of the hernia, which occurs when the protruding tissue swells and cuts off the blood supply to the loop of intestine within it. The strangulated intestine can become gangrenous, which can be life-threatening. Obstructed and strangulated hernias require immediate medical attention, Ephgrave warns.

The rate of success for a first-time groin hernia surgery is more than 90 percent. "Follow your physician's advice about limits on your physical activity for the first few months after surgery, because activity that strains the muscles in that time period can cause the hernia to return," Ephgrave says.

For more information about hernias, talk to your physician.