Peptic ulcers involve a break or erosion in the mucosal layer that leads to an open sore. Peptic ulcers generally occur in the stomach or proximal duodenum. When a peptic ulcer occurs in the stomach, it is called a gastric ulcer. When it occurs in the duodenum, it is called a duodenal ulcer. Most gastric ulcers tend to occur at the junction of the fundus and antrum along the lesser curvature of the stomach.

Complications of a peptic ulcer include hemorrhage, perforation, and gastric outlet obstruction. A lot of blood can be lost quickly with an actively bleeding ulcer. This can lead to circulatory shock as the blood pressure of an individual drops dangerously low. Blood from an ulcer can be seen in vomit and can also cause dark stools. Typically, the pain associated with an ulcer worsens with an empty stomach.

The two most significant risk factors for peptic ulcer development are a H. pylori infection and the chronic use of NSAIDs like aspirin. Pharmacologic treatment of ulcers focuses on stopping NSAID use or getting rid of H. pylori, relieving symptoms, and healing of the ulcer crater.