Most hernias occur when part of the bowel or peritoneum pushes through a gap in the abdominal wall. The peritoneum is the membrane that lines the abdominal cavity and (completely or partly) encloses most of the organs in the abdomen. The protruding pouch, called the hernia or hernial sac, may contain parts of organs such as the bowel or stomach. A bulge can usually be seen from the outside. Whether or not a hernia causes problems will depend on where it is and how big it is.
These are the most common types of hernias:
- Inguinal hernias: entsteht occur at a weak spot above the inguinal ligament, which is above the groin. This is the most common kind of hernia. They usually affect men.
- Femoral hernias: occur in the upper part of the thigh, below the inguinal ligament. They mainly affect women.
- Incisional hernias: occur in scar tissue from previously made surgical incisions (cuts). The abdominal wall is weaker there, so hernias are more likely.
- Umbilical hernias: arise at a weak point in the abdominal wall near the belly button (navel). They are most common in babies and overweight adults.
- Epigastric hernias: where tissue pokes through a gap in the abdominal wall between the breastbone and the belly button.
Diaphragmatic hernias are a little different because you can't see them from the outside. They occur when one of the gaps in the diaphragm becomes bigger and the peritoneum or part of the stomach moves up into the chest area from the abdomen. Hernias that you can't see from the outside are sometimes referred to as "internal hernias."
Most hernias don't go away on their own. One exception is umbilical ("belly button") hernias in babies. These usually go away on their own within the first two years of the baby’s life.
The most common types of hernia
Most hernias can be felt or even seen as bulges. They don't always cause symptoms. But they might lead to pain, burning, a feeling of pressure or a pulling sensation, especially during physical strain. Some people only have symptoms when they tense their abdominal (tummy) muscles a lot.
If a section of the bowel is pinched by the hernia, people may have problems with their digestion. In men who have an inguinal hernia, tissue may poke into a scrotum, making it swell a lot (scrotal hernia).
Severe or sudden new pain in the area of the hernia, or nausea and vomiting in addition to pain, could be signs that the hernia sac has become blocked or cut off. This can lead to serious complications such as peritonitis (inflammation of the peritoneum).
Large, clearly visible hernias are very unpleasant and can be quite distressing.
The symptoms caused by diaphragmatic hernias are different to the symptoms caused by hernias that poke out through gaps in the abdominal wall (abdominal wall hernias). These internal hernias can lead to heartburn, trouble swallowing and breathing difficulties. The symptoms can be treated with medication and the hernia can be fixed through surgery.
Causes and risk factors
Two factors that increase the risk of hernias are weak abdominal muscles and weak connective tissue. Some people are born with weak connective tissue, whereas in others it becomes weaker in older age. Illnesses or surgery can also weaken tissue and muscles.
Being very overweight increases the pressure in your abdomen. But this only increases the risk of incisional and umbilical hernias. It doesn’t affect the risk of inguinal hernias. Tumors or a build-up of fluid in the abdomen can increase the pressure on the abdominal wall too.
Abdominal wall hernias are also more common in pregnant women. Smoking and illnesses like diabetes can make it more difficult for wounds to heal properly after surgery, which makes incisional hernias more likely.
Lifting heavy objects, coughing and straining can make existing hernias grow in size. Whether these things can also cause hernias in the first place probably depends on the type of hernia. It isn’t clear whether this is the case with inguinal hernias, for example.
Inguinal hernias are the most common type of hernia: About 25 out of 100 men and 2 out of 100 women have at least one inguinal hernia at some point in their lives. The second most common types of hernia are umbilical and incisional hernias. Depending on the kind of surgery done, up to 15 out of 100 people develop incisional hernias following surgery that involves cutting their abdominal wall. Epigastric hernias, femoral hernias and diaphragmatic hernias are less common.
If left untreated, hernias can get bigger over time, become more visible and cause more problems. These problems are rarely serious, though.
But sometimes the hernia sac becomes constricted and may, for instance, trap part of the bowel. This can cause the bowel to become blocked (obstruction), which leads to severe pain, nausea and vomiting. The likelihood of this happening is greater with femoral hernias than with inguinal hernias, for instance, because the opening is narrower.
If the blood vessels are pinched too, the tissue in the hernia sac might die and result in peritonitis (inflammation of the peritoneum). In rare cases, the skin covering the hernia may thin out and die. If that happens, the area may become inflamed or the hernia might break through the skin.
Pinched ("strangulated") hernias are always an emergency and must be operated on within a few hours. So it's best to call the emergency services immediately (112 in Germany and most European countries, or 911 in the U.S.) or ask someone to drive you to the hospital.
Hernias are often clearly recognizable as such. The doctor first takes a look while the patient is standing, after asking them to tense their stomach muscles and cough. Then the patient is asked to lie down. This makes it easier for the doctor to feel how big the hernia sac is and see whether it can be pushed back into the abdomen. A stethoscope can be used to listen for bowel sounds in the hernia sac.
Whether and how hernias can be prevented depends on the type of hernia. To prevent incisional hernias, it’s a good idea to avoid strain due to things like carrying heavy objects following surgery at first. If the risk of recurrence is very high, a synthetic mesh can be used as a preventive measure.
Losing weight can lower the risk of incisional and umbilical hernias ("after surgery" and "belly button" hernias). But weight loss won't lower the risk of inguinal (groin) hernias. It's not clear whether carrying heavy objects makes inguinal hernias more likely.
Stopping smoking can help surgical wounds heal better, which probably lowers the risk of incisional hernias. It is also important to make sure that medical conditions like diabetes and anemia are treated properly because they can affect how well wounds heal too.
Surgery is the only treatment option for hernias. It involves pushing the hernia sac back into the abdomen or removing it, and closing the gap in the abdominal wall with stitches. A fine synthetic mesh is usually placed on the affected area too, to strengthen the abdominal wall and prevent the hernia from coming back.
In open surgery, the operation is carried out through a larger cut where the hernia is. In minimally invasive surgery (also called laparoscopic or keyhole surgery), several smaller cuts are made. The abdomen or abdominal wall are operated on by inserting surgical instruments and a fine tube with a camera attached to it (laparoscope) through the cuts. The camera enables the surgeon to see the inside of the abdomen on a screen. The surgery options will depend on things like the type and size of the hernia.
Hernias don’t always have to be operated on. If they aren’t causing any problems and the risk of complications is low, surgery isn’t needed. This is also true in people who are very old, weak or seriously ill and have a hernia that doesn’t pose an acute risk. People who have an inguinal hernia, on the other hand, are usually advised to have surgery.
Hernia supports or hernia belts (tight, belt-like bandages) were often used in the past to try to stop hernias from bulging out of the abdomen. This is not recommended nowadays, though, because they don’t make the hernia go away and can have side effects such as pressure ulcers (bedsores).
When people are ill or need medical advice, they usually go to see their family doctor or pediatrician first. Read about how to find the right doctor, how to prepare for the appointment and what to remember.
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