An abdominal wall hernia is when a hole develops in an area of weakness in the abdominal wall, that allows fat or bowel to push through. This is visible as a lump under the skin.

Hernias can occur anywhere on the abdominal wall but commonly form in the following sites:

• The groin (inguinal and femoral hernias)
• The belly button (umbilical hernia)
• Between the breast bone and the belly button (epigastric hernia)
• Through the site of a previous surgical incision, beneath or next to the scar (incisional hernia)
• On the side between the muscle layers of the abdominal wall (spigelian hernia)

(Note: Hiatus hernias are different and this information is not relevant to hiatus hernias)

In some patients it is unclear why a hernia has developed. In many, there is a history of long term abdominal straining from:

• Constipation
• Difficulty passing urine
• Chronic coughing
• Heavy lifting

Pregnancy also increases pressure on the abdominal wall and can lead to hernias. Surgical scars are a site of weakness and are a common site for hernias to develop.

Not all hernias cause symptoms. Common symptoms include:

• A lump that can change in size (it may disappear when lying down and bulge when standing, lifting or coughing)
• Pain that can be a dull ache and may be worse with activity, or a sharp pain with coughing or sneezing

Occasionally hernias can become trapped (incarcerated) and the lump may become hard and quite painful. If bowel is trapped in a hernia this can cause a bowel obstruction with nausea and vomiting and abdominal swelling. The blood flow to the trapped bowel may become blocked. Trapped hernias require emergency surgery and you should go directly to your hospital emergency department.

Hernias are usually diagnosed by clinical examination and a scan is often not required. Sometimes an ultrasound or CT scan is needed to confirm a hernia is present or to provide more information to plan surgery.

Not all hernias need to be treated right away, especially if they are small and not causing symptoms. Most hernias are repaired with surgery and this may be done with either open surgery or keyhole (laparoscopic) surgery. Your surgeon will advise you of the best treatment option for your hernia.