What is a peptic ulcer? A peptic ulcer is a localized area of erosion occurring in the stomach or duodenal (the beginning of the small intestine) lining, resulting in abdominal pain, possible bleeding, and other gastrointestinal symptoms. The most common cause of peptic ulcer is a stomach infection associated with the Helicobacter pylori (H pylori) bacteria. Many people contract H pylori at a young age, but symptoms most commonly occur in adulthood. In some people, H pylori bacteria cause an infection in the lining of the stomach, which may lead to peptic ulcers. Damage to the stomach lining from stomach acid increases the likelihood that H pylori infection will result in an ulcer. Other risk factors for peptic ulcer include alcohol use, tobacco use, and medications such as aspirin and nonsteroidal anti-inflammatory drugs (NSAIDS). Severe illness has also been associated with development of peptic ulcers. The signs and symptoms of peptic ulcer can be constant or sporadic, and the disease course varies among individuals. If infection with H pylori bacteria is the cause, the symptoms will remain as long as the infection is untreated. Some people with peptic ulcers have no symptoms at all, while others may have burning pain, severe nausea, and vomiting. In the case of H pylori-related peptic ulcers, the infection can be treated successfully with antibiotics. For peptic ulcers not related to H pylori, antacids and other medications are an effective treatment. You can reduce your risk of H pylori bacteria infection by following commonsense hygiene practices, such as washing your hands with soap and water before preparing food and after handling dirty diapers or using the bathroom. Seek immediate medical care (call 911) for serious symptoms such as severe abdominal pain; bloody or black tarry stools; or vomiting blood or black material (resembling coffee grounds). Seek prompt medical care if you are being treated for peptic ulcer but mild symptoms recur or are persistent.