Helicobacter pylori infection and peptic ulcers

Nearly all peptic ulcers are caused by either Helicobacter pylori infection or the use of non-steroidal anti-inflammatory drugs (NSAIDs), which include aspirin. As H. pylori infection is becoming less prevalent in developed countries, NSAIDs are an increasingly important cause of ulceration, including ulcers complicated by gastrointestinal (GI) bleeding. Only about 15% of H. pylori-infected people develop an ulcer in their lifetime, with the risk determined by virulence of the H. pylori strain, host genetics and environment (particularly smoking).