What is a Hernia?
A hernia is a weakness or tear in the abdominal muscles that allows organs such as intestines or fatty tissue to protrude through the weakened area. This can cause a noticeable bulge under the skin as well as pain and discomfort. Symptoms can worsen when standing for long periods or when straining the abdominal muscles, such as when lifting heavy objects.Hernia image
Hernias can develop in the groin (inguinal hernia), around the navel (umbilical hernia) or in the area of any surgical incision (ventral hernia). Some hernias are present at birth while others develop slowly over a period of months or years. Hernias can also come on quite suddenly.
Think of a hernia as a bulge in a tire. The outer wall of the tire is like your abdominal wall. The inner tube of the tire is like your intestines. Most of the time, the outer wall of the tire is strong enough to hold the inner tube, but if the wall weakens, a bulge may occur. This is similar to the way a hernia might form in the abdominal wall.
What Causes a Hernia?
Many hernias are the result of a defect or weakness in the abdominal wall that was present at birth. The area can be weakened by age or injury and can especially be weakened by a previous surgical incision. Although some hernias are more common in men, they can develop in anyone. Risk factors for a hernia include:
Straining while lifting heavy objects
Straining during bowel movements or urination
Certain medications such as steroids
Types of Hernias
All hernias are not created equal. They are characterized by their location in the abdominal wall and occasionally by their specific cause. There are five types of hernias:
Ventral or abdominal hernias occur when the intestine pushes through a weakening in the abdominal wall. They are frequently referred to as incisional hernias because the bulge often occurs at the site of a previous surgical incision. An incisional hernia is located at the site of a previous surgical incision. Any area that has previously been operated on will remain somewhat weakened throughout his/her lifetime. Hernias can develop in these incisions during the weeks, months or even years after the initial operation. There are many factors that can affect the formation of an incisional hernia including smoking, weight, other medical problems and the type of healing tissue the patient naturally develops after a surgical incision.
An umbilical hernia occurs in the naturally weakened area of the navel or belly button where the umbilical cord was attached. These are frequently seen in children, but are also often seen in adults. In small children, umbilical hernias will usually fade away as the child ages. In adults, the only way to treat an umbilical hernia is through surgery.
An inguinal hernia is the most common type of hernia- about two percent of all men will develop this type of hernia during their lifetime. Inguinal hernias occur in men about five times more frequently than in women due to a potential weak spot in the groin when a male's testicles descend during fetal development. An indirect inguinal hernia is the type of hernia that develops in this weak spot. The hernia may then descend into the scrotum in men or, in women, to the outer folds of the vagina. Later in life, the hernia follows this path and descends along the cord into the testicle. About 70 percent of inguinal hernias are indirect.
A direct inguinal hernia is less common and occurs very near the indirect inguinal hernia in the groin. A direct hernia can be referred to as a "wear and tear" hernia, as weak tissue here can be aggravated by straining or lifting over time.
Femoral hernias are most common in women and occur when there is a weakness near the femoral artery in the upper thigh.
Hiatal hernias occur when the stomach and esophagus slide up through the diaphragm into the chest. Common symptoms are heartburn or Gastroesophageal Reflux Disease (GERD). Paraesophageal hernias occur when part of the stomach is squeezed up into the chest beside the esophagus. The stomach can be strangulated, restricting blood supply to the related tissues.
About 10% of people develop some type of hernia during their lifetime. Hernias are seven times more common in males than in females.
Over 1 million abdominal wall hernia repairs are performed each year, with inguinal hernia repairs constituting nearly 770,000 of these cases.9,10,11
Approximately 25% of males and 2% of females have inguinal hernias in their lifetimes; this is the most common hernia in males and females.11,12
Approximately 75% of all hernias occur in the groin; two thirds of these hernias are indirect and one third direct.
Indirect inguinal hernias are the most common hernias in both men and women; a right-sided predominance exists.
ncisional and ventral hernias account for 10% of all hernias.4
Only 3% of hernias are femoral hernias.
Indirect hernias may not appear until middle or old age.
Direct hernias occur in older patients as a result of relaxation of abdominal wall musculature and thinning of the fascia.