A hernia occurs when part of an organ (usually the intestines) sticks through a weak point or tear in the thin muscular wall that holds the abdominal organs in place.

There are several types of hernias, based on where it occurs:

• Inguinal hernia appears as a bulge in the groin or scrotum. This type is more common in men than women.
• Femoral hernia appears as a bulge in the upper thigh. This type is more common in women than in men.
• Incisional hernia can occur through a scar if you had abdominal surgery.
• Umbilical hernia appears as a bulge around the belly button. It occurs when the muscle around the navel doesn't close completely.

Usually, there is no obvious cause of a hernia, although they are sometimes associated with heavy lifting.

Hernias can be seen in infants and children. This can happen when the lining around the abdominal organs does not close properly before birth. About 5 out of 100 children have inguinal hernias (more boys than girls). Some may not have symptoms until adulthood.

If you have any of the following, you are more likely to develop a hernia:

• Family history of hernias
• Cystic fibrosis
• Undescended testicles
• Extra weight
• Chronic cough
• Chronic constipation, straining to have bowel movements
• Enlarged prostate, straining to urinate

• Groin discomfort or groin pain aggravated by bending or lifting
• A tender groin lump or scrotum lump
• A non-tender bulge or lump in children

A doctor can confirm the presence of a hernia during a physical exam. The mass may increase in size when coughing, bending, lifting, or straining. The hernia (bulge) may not be obvious in infants and children, except when the child is crying or coughing.

Most hernias can be pushed back into the abdominal cavity. However, if it cannot be pushed back through the abdominal wall, this can lead to a strangulated loop of intestine. If left untreated, this portion of the intestine dies because of loss of blood supply.

Almost all hernias require surgery, preferably before complications occur, to reposition the herniated loop of intestine and secure the weakened muscles in the abdomen.

For information on such surgery, see: Hernia repair

The outcome is usually good with treatment. Recurrence is rare (1-3%).

An incarcerated hernia can lead to a strangulated intestine, which can result in gangrene, a life-threatening condition requiring emergency surgery. In rare cases, inguinal hernia repair can damage structures involved in the function of a man's testicles.

Another risk of hernia surgery is nerve damage, which can lead to numbness in the groin area.

Call your doctor right away if:

• You have a hernia and the contents cannot be pushed back into the abdomen using gentle pressure
• You develop nausea, vomiting, or a fever with your hernia
• The hernia becomes red, purple, dark, or discolored

Call your doctor if:

• You have groin pain, swelling, or a bulge
• An umbilical hernia fails to heal on its own by the time your child is 5 years old

• Use proper lifting techniques.
• Lose weight if you are overweight.
• Relieve or avoid constipation by eating plenty of fiber, drinking lots of fluid, going to the bathroom as soon as you have the urge, and exercising regularly.

Patient Care Committee. Society for Surgery of the Alimentary Tract. Surgical repair of groin hernias. SSAT patient care guidelines. J of Gastrointestinal Surgery. 2004; 8(3): 365-6.

Hachisuka T. Femoral Hernia Repair. Surg Clin North Am. 2003; 83(5): 1189-1205.

Awad SS. Current approaches to inguinal hernia repair. Am J Surg. 2004; 188(6A Suppl): 9S-16S.