Occasionally the muscle wall of the abdomen develops a small hole or rupture allowing internal tissue, such as a small section of an internal organ to protrude through – this is a hernia (derived from the Latin word for 'rupture').
Hernias typically form in specific sites in the body's muscle wall and are often specific to gender. The most common type of hernias are groin hernias and are more common in men. Men have a 1 in 4 chance of developing this type of hernia during their lifetime, whereas women have only a 1 in 30 chance.
Hernias are classified as either 'reducible' or 'non-reducible'. This simply refers to whether the protrusion can be pushed back into the internal cavity (reducible) or not (non-reducible). Of the two types, a non-reducible hernia requires immediate surgical correction, as this type of hernia is prone to complications if the contents become trapped, known as strangulation.
Common hernia types
Inguinal hernias are the most common type of hernias. They develop between the abdominal area and the groin. Although they occur in both men and women, they are slightly more common in men. They are more likely to occur after the age of 40 and are often related to ‘wear-and-tear’ on the abdominal muscles, e.g. heavy weights, lifting, constipation, cough.
This type of hernia is more common in women than in men, and they develop in the lower section of the abdominal area and push through the muscle wall into the thigh and area around the groin.
This type specifically develops after surgery in scarring which has not healed properly. A similar type of hernia may appear after stoma surgery, in which case it is referred to as a 'parastomal hernia'.
The navel is a natural weak spot in the muscle wall and so hernias often develop here (in fact if you have an 'outie' belly button this is a type of umbilical hernia).
Different types of hernia have different symptoms. The most common symptom is where a bump or lump develops under the skin. Hernias can cause pain or discomfort, in which case they should be repaired.
Hernias can be due to:
- Age – the strength of the muscle wall naturally decreases with age.
- Ascites – a condition where fluid builds up in the abdominal cavity.
- Body weight – any increase in body weight places greater stress on the muscle wall.
- Genetics – some people inherit physiological characteristics where there is a weakness in a specific part of the muscle wall.
- Previous surgery – in the case of incisional hernias.
- Pregnancy – especially after multiple pregnancies.
Tests & Diagnosis
The first step in diagnosing whether a hernia is present is a physical examination and review of medical history. At times, imaging tests such as ultrasound or CT scan are also used as an adjunct.
Hernias that do not cause any symptoms at all do not necessarily require surgery. When symptoms are present or the lump is getting bigger, surgery is required. Non reducible hernias are regarded as a medical emergency and require immediate hernia surgery.