Sore that develops in the mucous membrane of the stomach (more frequent in women) or duodenum (accounting for 80% of ulcers and more frequent in men) when its ability to resist acid in gastric juice is reduced.
It causes burning ache and hungerlike pain. Ulcers can bleed, perforate the abdominal wall, or block the gastrointestinal tract. Stress and diet were blamed until Helicobacter pylori bacteria and long-term use of aspirin and similar drugs were shown to be the two major causes. The former is treated with combination drug therapy and the latter by stopping the causative drugs if possible or with drugs that reduce acid production. A rare cause is Zollinger-Ellison syndrome, in which a tumour causes increased acid secretion. Cigarette smoking slows healing and promotes recurrence.