A hernia is where an internal part of the body pushes through a weakness in the muscle or surrounding tissue wall.
The muscles are usually strong enough to keep the organs in place. However, a weakness may cause a hernia to occur.
Types of hernia
Hernias can occur anywhere in your abdomen (the area of your body between your chest and hips).
There are several different types of hernia, which are described below.
- Inguinal hernias – occur when part of your bowel pokes through your lower abdomen into your groin.
- Femoral hernias – occur when fatty tissue or a part of your bowel pokes through into your groin, at the top of your inner thigh.
- Incisional hernias – occur when tissue pokes through a surgical wound in your abdomen that has not fully healed.
- Umbilical hernias – occur when fatty tissue or a part of your bowel pokes through your abdomen near your navel (belly button).
- Hiatus hernias – occur when part of your stomach pushes up into your chest by squeezing through an opening in the diaphragm (the thin sheet of muscle that separates the chest from the abdomen).
- Epigastric hernias – occur when fatty tissue pokes through your abdomen, between your navel and the lower part of your sternum (breastbone).
- Spigelian hernias – occur when part of your bowel pokes through your abdomen at the side of your abdominal muscle, below your navel.
- Muscle hernias – occur when part of a muscle pokes through your abdomen; muscle hernias can also occur in leg muscles as the result of a sports injury.
How common are hernias?
Different types of hernia tend to affect different groups of people. About three-quarters of all abdominal hernias are inguinal hernias.
Inguinal hernias are the most common type of hernia, and account for three out of four hernia cases.
About 1 in 4 men and 3 in every 100 women will have an inguinal hernia at some point during their lifetime.
Risk factors for inguinal hernias include:
- sex – they are more common in men than in women
- age – your risk of developing one increases as you get older
- being obese – having a body mass index (BMI)of 30 or over
- doing lots of heavy lifting
- having a long-term cough
- having long-term constipation (an inability to empty your bowels)
Femoral hernias are less common than inguinal hernias.
Femoral hernias are about four times more common in women than men, and can affect women of any age. Apart from sex and age, femoral hernias have similar risk factors to inguinal hernias.
Incisional hernias can develop as a complication of abdominal surgery. The risk of an incisional hernia developing after surgery will vary depending on the type of surgery involved.
Umbilical hernias are very common in infants, particularly in black infants. The reasons why they tend to affect black infants more are unclear.
In 9 out of 10 cases, an umbilical hernia will get better without treatment as a child gets older.
Hiatus hernias are common, affecting up to 1 in 10 people.
They do not always cause symptoms, although in some people they can cause heartburn (pain or discomfort in the chest that usually occurs after eating).
Assessing and treating hernias
A hernia will often be assessed using an ultrasound scan, which uses high-frequency sound waves to create an image of part of the inside of the body.
In many cases, hernias cause no (or very few) symptoms. However, there is a chance that a hernia could:
- cause an obstruction in the bowel
- interrupt the blood supply to the herniated tissue (known as a strangulated hernia)
Both are medical emergencies. If they occur, you should go immediately to the accident and emergency (A&E)department of your nearest hospital.
Due to potential risks associated with these complications, surgery to repair a hernia is usually recommended.
The exceptions to this are umbilical hernias, which usually get better on their own, and hiatus hernias, which are sometimes initially treated with medication. In some cases, surgery is also needed for hiatus hernias.
Read more about treating hiatus hernias.
If you have a hernia, whether or not you will need surgery will depend on:
- where the hernia is located – femoral hernias and hernias in the groin are more likely to require surgery; abdominal hernias less likely
- your symptoms – some hernias may not cause symptoms, others may be painful
- the content of your hernia – the hernia may consist of part of your bowel, muscle or other tissue
If you need surgery, your surgeon will explain the benefits and risks of the procedure to you in detail.