What Causes Ulcers?

Medical Author: Melissa Stöppler, M.D.
Medical Editor: Jay W. Marks, MD

A peptic ulcer is an area of damage to the inner lining of the stomach, esophagus, or duodenum (the first part of the small intestine). Over 25 million Americans will have a peptic ulcer at some point in their lifetime. People of all ages can suffer from ulcers. Men and women are equally affected.

Peptic ulcers were formerly thought to be caused by stress, coffee consumption, or spicy foods. Now it is clear that about 60% of peptic ulcers are caused by a bacterial infection that can usually be cured. Another 20% are caused by nonsteroidal antiinflammatory drugs (NSAIDs) such as aspirin and ibuprofen (Advil, Nuprin, etc.), and another 20% have miscellaneous causes such as cigarettes or no clear cause.

The bacterium Helicobacter pylori (H. pylori) was established as the leading cause of peptic ulcers in the early 1980s. It was also found to cause gastritis (inflammation of the stomach lining), and, in Asian populations, cancer of the stomach.

H. pylori is a spiral-shaped bacterium that can live and grow on the lining tissues of the stomach. Some people can be infected with H. pylori and never develop an ulcer or show any symptoms of the infection. In other people, the organism may persist for years before any symptoms develop.