Peptic ulcers are open sores that develop on the inside lining of your stomach and the upper portion of your small intestine. The most common symptom of a peptic ulcer is stomach pain.

Peptic ulcers include:

Gastric ulcers that occur on the inside of the stomach
Duodenal ulcers that occur on the inside of the upper portion of your small intestine (duodenum)

The most common causes of peptic ulcers are infection with the bacterium Helicobacter pylori (H. pylori) and long-term use of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) (Advil, Aleve, others). Stress and spicy foods do not cause peptic ulcers. However, they can make your symptoms worse.