Causes
Although stress and spicy foods might make the symptoms of peptic ulcer worse, they aren't the cause of the condition as was once thought.
A bacterium called Helicobacter pylori (H. pylori) causes most ulcers - about 80% to 85% of duodenal ulcers and 60% to 80% of gastric ulcers. The bacteria can spread into the mucus lining that usually protects the stomach and small intestine from digestive acids, damaging it in the process. Roughly a two-thirds of Americans are infected with these bacteria, but only 10% to 20% of these people will actually develop stomach problems.
The other major cause of peptic ulcer disease is the use of aspirin* and other nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs can penetrate the lining of the stomach and release substances that damage cells. NSAIDs also block natural chemicals called prostaglandins that can help to protect and repair those cells.
Excessive alcohol use can put people at higher risk for peptic ulcer disease, but it isn't a true cause. About 1 in 10 people will get an ulcer at some point in their lives, although it's rare before the age of 30.