A hernia occurs when an internal part of the body pushes through a weakness in the muscle or surrounding tissue wall.
In many cases, hernias cause no or very few symptoms, although you may notice a swelling or lump in your tummy (abdomen) or groin.
The lump can often be pushed back in, or will disappear when you lie down. Coughing or straining may make the lump appear.
Types of hernia
Hernias can occur throughout the body, but they most often develop in the area of your body between your chest and hips. Some of the more common types of hernia are described below.
Inguinal hernias occur when fatty tissue or a part of your bowel pokes through into your groin at the top of your inner thigh.
This is the most common type of hernia and it mainly affects men. It is often associated with ageing and repeated strain on the abdomen.
Femoral hernias also occur when fatty tissue or a part of your bowel pokes through into your groin at the top of your inner thigh. They are much less common than inguinal hernias and tend to affect more women than men.
Like inguinal hernias, femoral hernias are also associated with ageing and repeated strain on the abdomen.
Umbilical hernias occur when fatty tissue or a part of your bowel pokes through your abdomen near your belly button (navel).
This type of hernia can occur in babies if the opening in the abdomen through which the umbilical cord passes doesn't seal properly after birth. Adults can also be affected, possibly as a result of repeated strain on the abdomen.
Hiatus hernias occur when part of the 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). This type of hernia may not have any noticeable symptoms, although it can cause heartburn in some people.
It's not exactly clear what causes hiatus hernias, but it may be the result of the diaphragm becoming weak with age or pressure on the abdomen.
Other types of hernia
Other types of hernia that can affect the abdomen include:
Incisional hernias – these occur when tissue pokes through a surgical wound in your abdomen that has not fully healed.
Epigastric hernias – these occur when fatty tissue pokes through your abdomen, between your navel and the lower part of your breastbone (sternum).
Spigelian hernias – these occur when part of your bowel pokes through your abdomen at the side of your abdominal muscle, below your navel.
Diaphragmatic hernias – these occur when organs in your abdomen move into your chest through an opening in the diaphragm. This can affect babies if their diaphragm does not develop properly in the womb, but can also affect adults.
Muscle hernias – these occur when part of a muscle pokes through your abdomen. They can also occur in leg muscles as the result of a sports injury.
When to seek medical advice
You should see your GP if you think you have a hernia, so they can determine whether you need to be referred for surgical treatment.
You should go the accident and emergency (A&E) department of your nearest hospital immediately if you have a hernia and you develop any of the following symptoms:
sudden, severe pain
difficulty passing stools (constipation) or wind
the hernia becomes firm or tender, or cannot be pushed back in
These symptoms could mean that the blood supply to a section of organ or tissue trapped in the hernia has become cut off (strangulation), or that a piece of bowel has entered the hernia and become blocked (obstruction).
A strangulated hernia and obstructed bowel are medical emergencies and need to be treated as soon as possible.
Your GP will usually be able to identify a hernia by examining the affected area.
In some cases, they may decide to refer you to a nearby hospital to have an ultrasound scan to confirm the diagnosis or assess the extent of the problem. This is a painless scan where high-frequency sound waves are used to create an image of part of the inside of the body.
Once a diagnosis has been confirmed, your GP or hospital doctor will determine whether surgery to repair the hernia is necessary.
A number of factors will need to be taken into consideration when deciding whether surgery is appropriate, including:
The type of hernia – some types of hernia are more likely to become strangulated, or cause a bowel obstruction, than others.
The content of your hernia – if the hernia contains a part of your bowel, muscle or other tissue, there may be a risk of strangulation or obstruction.
Your symptoms and the impact on your daily life – surgery may be recommended if your symptoms are severe or getting worse, or if the hernia is affecting your ability to carry out your normal activities.
Your general health – surgery may be too much of a risk if your general health is poor.
Although most hernias will not get better without surgery, they will not necessarily get worse. In some cases, the risks of surgery will outweigh the potential benefits.
There are two main ways surgery for hernias can be carried out:
Open surgery – where one cut is made to allow the surgeon to push the lump back into the abdomen.
Keyhole (laparoscopic) surgery – this is a less invasive, but more difficult, technique where several smaller cuts are made, allowing the surgeon to use various special instruments to repair the hernia.
Most people are able to go home the same day or the day after surgery and make a full recovery within a few weeks.
If you doctor recommends having surgery, it is important to be aware of the potential risks, as well as the possibility of the hernia recurring. Make sure to discuss the benefits and risks of the procedure with your surgeon in detail before having the operation.