The two most common causes of peptic ulcer disease are infection with Helicobacter pylori (H. pylori) bacteria and use of nonsteroidal anti-inflammatory drugs (NSAIDs).

Although many people are infected with H. pylori bacteria, only a few of them will develop peptic ulcer disease. Certain factors make a person with an H. pylori infection more likely to get an ulcer. Some of these factors, not all of which are well understood, include:

• The use of certain medicines, such as aspirin, ibuprofen (Advil, Motrin), or other NSAIDs.
• Smoking.
• Excessive alcohol use.
• Prior history of ulcers.
• Physical stress caused by a severe illness or injury (such as a major trauma, the need to be on a ventilator to assist breathing, or surgery).

Most peptic ulcers that are not caused by an H. pylori infection are caused by the use of NSAIDs. NSAIDs may be prescribed to control pain or inflammation caused by long-term (chronic) diseases such as arthritis or headaches. When used for weeks or months, NSAIDs can damage the lining of the digestive tract, causing an ulcer or making an existing ulcer worse.

A rare cause of peptic ulcers is Zollinger-Ellison syndrome. In this condition, the stomach greatly overproduces acid, damaging the stomach lining.

Although there is no evidence to prove that emotional or mental stress causes ulcers, it does seem to make ulcers worse in some people. But the connection is still controversial. And there are no specific recommendations for using counseling or psychotherapy to treat peptic ulcers.