Updated 20 December 2017

Causes of peptic ulcers

Various factors can cause the lining of the stomach, the oesophagus, and the small intestine to break down, leading to peptic ulcers.


Until the middle of the 1980s, it was believed that the major causes of ulcers were stress, the genetically linked secretion of excessive stomach acid, eating too much fatty, rich and spicy food, and drinking too much alcohol, coffee and colas. It was also believed that certain personality types were more susceptible to peptic ulcers.

Helicobacter pylori

The viewpoint was that all these factors contributed to an excessive production of stomach acids, which eroded the protective lining of the stomach, duodenum or oesophagus.

Research from Australia in the 1980s revealed the presence of Helicobacter pylori in the stomachs of most patients with duodenal ulcers.  The duodenal ulcers arise on patches of gastric type mucosa in the duodenum where the acid from the stomach further damages the mucosa already affected by the Helicobacter pylori infection. 

Eradication of the infection healed the ulcers and prevented recurrent ulcers developing. The problem is that only certain types of Helicobacter pylori are associated with ulcers. Some strains are associated with cancer of the stomach and others may in fact, protect against “bad” varieties of Helicobacter taking up residence in the stomach. The indiscriminate eradication of these bacteria may be a disservice to the human host.

Gastric ulcers are more related to lifestyle factors such as smoking and the regular use of non-steroidal anti-inflammatory drugs such as aspirin, ibuprofen, indomethacin and naproxen.

Read more: 

Preventing peptic ulcers

The symptoms of peptic ulcers

Treating peptic ulcers

Revised and reviewed by Dr John P Wright MBChB, MRCP (UK), PhD. Gastroenterologist in private practice, Cape Town. February 2015

Previously reviewed by Prof Jan van Zyl, Department of Gastroenterology, University of the Free State, July 2011