Hernia 

A hernia occurs when an internal part of the body, such as an organ, pushes through a weakness in the muscle or surrounding tissue wall. The muscles are usually strong enough to keep the organs in place, but if they are not this can cause a hernia.

Types of hernia

A hernia can occur anywhere in your abdomen (the part of your body between the chest and the hips). There are several types of hernia:

• Inguinal hernia occurs when part of your bowel (part of your digestive system) pokes through your lower abdomen into your groin (the area at the front of the body where your thighs meet your abdomen).
• Femoral hernia occurs when fatty tissue or a part of your bowel pokes through into your groin, at the top of your inner thigh.
• Incisional hernia occurs when tissue pokes through a surgical wound in your abdomen that has not fully healed.
• Umbilical hernia occurs when fatty tissue or a part of the bowel pokes through your abdomen near your navel (belly button).
• Hiatus hernia occurs when part of your stomach pushes up into your chest by squeezing through an opening in the diaphragm (a large, thin sheet of muscle that separates your chest from your abdomen).
• Epigastric hernia occurs when fatty tissue pokes through your abdomen, between your navel and the lower part of your sternum (breastbone).
• Spigelian hernia occurs when part of your bowel pokes through your abdomen at the side of your stomach muscle, below your navel.
• Muscle hernia occurs when part of your muscle pokes through your abdomen and can also occur in the muscles in your leg, often as the result of a sports injury.

How common are hernias?

The different types of hernia tend to affect different groups of people. Around three-quarters of all abdominal hernias are inguinal hernias.

Inguinal hernias

Inguinal hernias are the most common type of hernia. In England, there are around 70,000 surgical operations to repair inguinal hernias every year. Over the course of a lifetime, just over a quarter of all men and 3 women in every 100 will have an inguinal hernia.

Risk factors for inguinal hernias include:

• your sex (they are more common in men)
• your age (they are more common as you get older)
• being obese (having a body mass index, or BMI, over 30)
• doing lots of heavy lifting
• having a chronic (long-term) cough
• having chronic constipation (an inability to empty your bowels)

Femoral hernias

Femoral hernias are less common than inguinal hernias, with around 3,400 femoral repair operations carried out in England in 2008-09. Femoral hernias are four times more common in women than in men. Apart from sex and age, they have similar risk factors to inguinal hernias.

Incisional hernias

Incisional hernias develop as a complication of abdominal surgery. The risk of an incisional hernia developing after surgery varies depending on the type of surgery involved.

Umbilical hernias

Umbilical hernias are very common in infants and are more common in black infants, although the reasons for this are unclear. In 9 out of 10 cases, an umbilical hernia will get better without the need for treatment as a child gets older.

Hiatus hernias

Hiatus hernias are very common, affecting up to 1 in 10 people. They do not always cause symptoms, although in some people they can cause heartburn (a burning chest pain or discomfort that usually occurs after eating).

Outlook

Hernias are often assessed using an ultrasound scan. This is a procedure that uses high-frequency sound waves to create an image of part of the inside of the body. See the Health A-Z topic about Ultrasound scans for more information about the procedure.

In many cases, hernias cause no (or very few) symptoms. However, there is a chance that the hernia could:

• cause an obstruction in the bowel
• interrupt the blood supply to the herniated tissue (known as a strangulated hernia)

Both of these are medical emergencies. If they occur, visit your nearest accident and emergency (A&E) department immediately.

Because of the potential risks of these complications, surgery is usually recommended to repair a hernia. The exceptions are umbilical hernias, as these usually get better on their own, and hiatus hernias, which are sometimes initially treated with medication. However, in some cases, surgery will also be required for hiatus hernias (see Hiatus hernia - treatment).

Whether you will need surgery will depend on:

• The location of your hernia. Femoral hernias and hernias in the groin are more likely to require surgery, whereas hernias in the abdomen are less likely to require surgery.
• The symptoms of your hernia. Some hernias may not cause any symptoms while others may be painful.
• The content of your hernia. The hernia may be made of part of your bowel, muscle or other tissue.

If surgery is necessary, the benefits and risks will be discussed with you, and your surgeon will explain the procedure.