A peptic ulcer is erosion in the lining of the stomach or duodenum (the first part of the small intestine). The word “peptic” refers to pepsin, a stomach enzyme that breaks down proteins. If a peptic ulcer is located in the stomach it is called a gastric ulcer.

Small ulcers may not cause any symptoms. Large ulcers can cause serious bleeding. Most ulcers occur in the first layer of the inner lining. A hole that goes all the way through is called a perforation of the intestinal lining. A perforation is a medical emergency.

Normally, the lining of the stomach and small intestines have protection against the irritating acids produced in your stomach. For a variety of reasons, the protective mechanisms may become faulty, leading to a breakdown of the lining. This results in inflammation (gastritis ) or an ulcer.

The most common cause of such damage is infection of the stomach with a bacterium called Helicobacter pylori (H.pylori). Most people with peptic ulcers have this organism living in their gastrointestinal (GI) tract. On the other hand, many people have this organism living in their GI tract but they don't get an ulcer.

Other factors can make it more likely for you to get an ulcer, including:

• Using aspirin, ibuprofen, or naproxen
• Drinking alcohol excessively
• Smoking cigarettes and using tobacco

In addition, if you have a family history of ulcers or you are blood type O, you are more likely to get a duodenal ulcer. There is also a rare condition called Zolliger-Ellison syndrome in which a tumor in the pancreas secretes a substance that causes ulcers throughout the stomach and duodenum.

Many people believe that stress causes ulcers. It is not clear if this is true. While critically ill patients who are on a breathing machine are at risk of so-called “stress ulceration,” everyday stress at work or home doesn't appear to cause peptic ulcers.

Abdominal pain  is a common symptom but it may not always be present. The abdominal pain from peptic ulcers can differ a lot from person to person. For example, the pain may get better or worse after eating a meal.

Other possible symptoms include:

• Nausea, vomiting
• Weight loss
• Fatigue
• Heartburn, indigestion, belching
• Chest pain
• Vomiting blood
• Bloody or dark tarry stools

It is important to note that you may have no symptoms at all from an ulcer.

To diagnose an ulcer, your doctor will order one of the following tests:

• An upper GI -- a series of x-rays taken after you drink a substance called barium.
• An esophagogastroduodenoscopy (EGD) -- a special test performed by a gastroenterologist in which a thin tube is inserted through your mouth into the gastrointestinal tract to look at your stomach and small intestines.

During an EGD, the doctor may take a biopsy from the wall of the intestines to test for H. pylori.

Your doctor may also order:

• Stool guaiac cards to test for blood in your stool
• Hemoglobin test to check for anemia