Conditions and diseases

Hiatal hernia

Symptoms and causes

Symptoms and causes

What is it?

The diaphragm (the muscle that separates the thoracic cavity from the abdominal cavity) has an opening through which the oesophagus proceeds from the chest to the abdominal cavity. A diaphragmatic hernia occurs when this opening is wider than necessary.

The transition from the oesophagus to the stomach is located exactly where the oesophagus passes through the diaphragm; there the oesophagus makes an acute angle (angle of His). This angle becomes sharper when the stomach is filled (when eating) and the diaphragm contracts. This angle then acts as a kind of valve and prevents stomach contents from flowing back into the oesophagus.

If this diaphragm opening is too wide, the natural ‘angular position’ between the stomach and the oesophagus is disturbed and the stomach contents can more easily recede into the oesophagus. This occurs more and more strongly when the patient lies flat on his or her back or bends forward, because gravity no longer helps to keep the acid in the stomach.

The terms abdominal rupture, hiatal hernia, diaphragmatic hernia and sliding hernia are usually used interchangeably, but they actually have different meanings. When the transition from the oesophagus to the stomach is located in the thoracic cavity, instead of the abdominal cavity, it is called a ‘sliding hernia’ (see image).

A diaphragmatic hernia can already be present at birth, and it can cause the small intestine and/or colon or spleen to enter the thoracic cavity. When it occurs later in life, it is usually due to a slackening of the diaphragm because of old age or, in rare cases, because of an accident (with a tear of the diaphragm).
An important risk factor for the development of a diaphragmatic hernia is increased pressure in the abdomen due to a greater amount of fatty tissue in the abdomen, chronic coughing, straining during bowel movements, pregnancy...


A diaphragmatic hernia does not in itself cause any symptoms, so it is usually discovered by accident. Typical symptoms of reflux are acid bursts, nagging and/or burning pain behind the sternum and swallowing problems. When the heartburn reaches the throat or mouth, it can cause local irritation, smelly breath and tooth erosion. This can also cause hoarseness (by acting on the vocal cords), coughs or asthma (by acting on the air pipes). When the reflux of gastric acid to the oesophagus is prolonged and regular, the oesophagus can become irritated and inflamed (refluxusophagitis), sometimes resulting in blood loss or constriction (stenosis).

During prolonged exposure, the mucous membrane of the oesophagus may gradually change (Barrett’soesophagus), which increases a person’s risk of developing adenocarcinoma (cancer) of the oesophagus.

Persistent reflux symptoms can lead to a lower quality of life due to poor sleep (reflux becomes worse when lying down flat) or because certain activities cannot be performed because one cannot bend over.

Diagnosis and treatment

Diagnosis and treatment

How is the diagnosis determined?


24-hour acid monitoring or pH-metry in principle is the gold standard. A thin probe is placed through the nose into the oesophagus just above the transition to the stomach and remains there for 24 hours. This enables continuous monitoring of the acidity. When the patient experiences discomfort, he or she must press a button. Later, when reading the acid measurement, we can check whether there was actually reflux at the time of the discomfort. It is important that this test is conducted without acid-inhibiting drugs.


The damage caused by heartburn can be viewed with a flexible camera during a gastroscopy . A diagnosis of oesophagitis or Barrett’s epithelium can also be made this way and, in case of suspicious abnormalities, biopsies can be taken from the mucous membrane for examination by microscope. A diaphragmatic hernia can also be diagnosed using this method.


A manometry is used to measure the pressure in the oesophagus (the contraction of the oesophagus and the pressure at the lower oesophageal ring muscle) with a thin probe. This method can be used to examined the relation between the reflux of the stomach contents, the strength of the sphincter (the sphincter has not been mentioned yet) and contractions of the oesophagus. Before planning an anti-reflux intervention, it is also important to exclude motility problems of the oesophagus (e.g. achalasia) based on this examination.


When taking a photo while swallowing (X-SMD or oesophageal-duodenum exam), the patient should drink a contrast agent while having X-rays taken to visualise the transition from the oesophagus to the stomach. This will allow for the identification of a diaphragmatic hernia and estimation of its size. In addition, passage (swallowing) problems or the reflux of contrast agent in the oesophagus can also be observed. The length of the oesophagus can be measured as well, which is important when considering surgical treatment.


Read more about the different treatments: Hiatus hernia repair

Treatment centres and specialisations

Treatment centres and specialisations

Latest publication date: 15/12/2023