Stomach ulcers are sores on the lining of the stomach. Contrary to popular belief, ulcers are not caused by stress or spicy foods, according to the American Academy of Family Physicians.
Most stomach ulcers are caused by a bacterium called Helicobacter pylori. The germ can erode the protective layer of mucus covering the stomach lining. When the stomach lining is exposed to the strong acids, ulcers can form.
Long-term use of nonsteroidal anti-inflammatory medications, such as aspirin, also can trigger ulcers. Limiting aspirin and related medications may reduce your risk.