Protrusions of part of an organ, usually the intestine, through a weakened muscle
- Obesity and lifting heavy weights may be risk factors
- Age and gender as risk factors depend on the type
- Genetics is not a significant factor
Hernias, commonly called “ruptures”, most often occur at sites in the abdomen where there is a weakness in the muscles. If pressure in the abdomen is increased due to activities such as lifting heavy weights, persistent coughing, or straining at defecation, the muscles of the abdomen become stretched at the weak point. A visible bulge can then develop, which may contain fatty tissue or part of the intestine. Abdominal hernias are frequently found in men who have manual jobs.
An abdominal hernia usually disappears when you lie flat, but sometimes a section of intestine becomes trapped inside the bulge. If the trapped portion of intestine becomes twisted, its blood supply may be cut off; this is known as a strangulated hernia. It causes worsening pain, nausea, and vomiting and is a medical emergency.
Hernias may occur in other areas. Hiatus hernias develop when part of the stomach protrudes into the chest cavity through a weak area in the diaphragm (the sheet of muscle that lies beneath the lungs and is involved in breathing,) and may be accompanied by gastro-oesophageal reflux disease.
What are the types?
Hernias are classified according to the site where they occur in the body. Some types occur more often in men; others are more frequently found in women.
This type of hernia occurs when a portion of the intestine pushes through into the inguinal canal, which is a weak spot in the abdominal muscle wall. The hernia causes a visible bulge in the groin or scrotum. These hernias usually affect men, but sometimes occur in women.
This type of hernia occurs in the part of the groin where the femoral vein and artery pass from the lower abdomen to the thigh. Women who are overweight or who have had several pregnancies are at increased risk of these hernias because their abdominal muscles are weakened.
Babies may be born with an umbilical hernia, which develops behind the navel due to a weakness in the abdominal wall. Hernias that develop near the navel are known as paraumbilical hernias and are most common in women who are overweight or have had several pregnancies.
Other types of hernia
Epigastric hernias develop in the midline between the navel and the breastbone and are three times more common in men. Incisional hernias may develop after abdominal surgery if there is weakness around the scar. Risk factors include being overweight and having several operations through the same incision.
What are the symptoms?
The symptoms may come on suddenly, but more often they develop over a period of several weeks or months. They may include the following:
A lump in the abdomen or groin; the lump may disappear when you lie down and reappear when you cough or strain to defecate.
A dragging or aching sensation in the abdomen or groin.
It is essential to consult a doctor if you think you have a hernia, even if it is not causing pain, because surgery may be needed to prevent the hernia from becoming strangulated or from causing intestinal obstruction.
The symptoms of a strangulated hernia usually come on suddenly and may include:
A steady pain that gradually gets worse.
Nausea and vomiting.
Swelling and redness around the hernia.
Pain when the hernia is touched.
Often, the hernia cannot be pushed back through the abdominal wall.
If you think you may have a strangulated hernia, you should get immediate medical help. A strangulated hernia is a medical emergency that requires urgent surgery to prevent the intestine from become gangrenous.
What might be done?
Your doctor may be able to feel a hernia by examining your abdomen or groin. Even small hernias eventually need to be repaired (see Hernia repair) because, if they are left untreated, they may become strangulated. A strangulated hernia requires immediate surgical repair. The type of operation depends largely on the size of the hernia and on your age and general health. Some procedures are done under local anaesthetic as day surgery and others under a general anaesthetic. Umbilical hernias in babies can usually be left untreated since they tend to disappear naturally by the age of 3–4 years. Surgery is usually effective. However, there is a risk that the hernia will recur in the same place or elsewhere. You can help to prevent a recurrence by losing any excess weight, taking gentle exercise, and avoiding constipation.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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