An ulcer is a sore on the lining of the stomach or duodenum. It can cause a variety of symptoms, including abdominal pain, heartburn, and nausea. If left untreated, an ulcer can lead to serious health complications, such as bleeding and perforation.
There are a number of ways to check for an ulcer. One common method is upper endoscopy. This procedure involves inserting a thin, lighted tube down the esophagus and into the stomach and duodenum. The doctor can then visualize the lining of these organs and look for any ulcers.