Causes of heartburn

Most people will experience heartburn if the lining of the oesophagus comes into contact with stomach acid for a period of time. The acid damages the delicate lining of the oesophagus, resulting in a burning, uncomfortable sensation.

To a certain extent, this is a normal occurrence in which the body’s anti-reflux barriers momentarily don’t work as they should. If you’ve had a heavy meal, for example, your stomach can remain swollen for a while – so much so that the lower oesophageal sphincter (LOS), the muscle between your oesophagus and stomach, can’t close properly. As a result, the acidic contents of your stomach may rise back up into your oesophagus, causing heartburn.

Some people experience more severe heartburn quite regularly but, when they’re examined, a clear cause or underlying condition can’t be found. These people are said to have functional heartburn. This affects about 20% of people and is more common in women than in men.

In others, a gastroscopy or other exam will identify an underlying cause or condition. Most often, the diagnosis is gastro-oesophageal reflux disease (GORD) – a condition where large volumes of stomach acid frequently flow up into the oesophagus and beyond, into the mouth or lungs.

This chronic condition can result from a structural or functional defect in the oesophagus. GORD is diagnosed when you develop symptoms or when the oesophagus becomes damaged (see article on GORD). 

Other possible causes of heartburn include:

Hiatus hernia

If you have this condition, a section of your stomach forms a pouch and protrudes into the chest through a small opening in your diaphragm. Hiatus hernia impairs the functioning of the lower oesophageal sphincter (LOS), which means it takes longer for acid to clear. 

Gastritis

This term describes inflammation of the stomach lining. Gastritis is also very common and can be caused by infection with the Helicobacter pylori bacterium, regular use of certain pain medications (e.g. aspirin, ibuprofen, naproxen), alcohol and increasing age. It’s often associated with heartburn and share many symptoms with GORD.

Stomach (peptic) ulcers

These are open sores that develop on the inside of the stomach. Almost all stomach ulcers are caused either by infection with Helicobacter pylori or pain medication. Ulcers can cause a burning sensation in the stomach and heartburn.

Reviewed by Dr Estelle Wilken, senior specialist in Internal Medicine and Gastroenterology at Tygerberg Hospital. March 2017.