Peptic Ulcer

A peptic ulcer is a mucosal defect that extends through the muscularis mucosae in an acid-exposed region of the stomach or duodenum. It develops when damaging forces overwhelm repair and protection—not simply because the stomach contains acid. The mucosal barrier depends on several linked defences: a mucus layer that limits contact between acid and epithelium, bicarbonate that helps maintain a near-neutral surface pH, intact epithelial junctions, adequate mucosal blood flow, and prostaglandin-mediated secretion and repair. Acid and pepsin are the main luminal aggressors. Infection, medications, smoking, impaired perfusion, and severe physiological stress can weaken the barrier or delay healing. Ulcer location reflects the balance between these forces. H. pylori-associated duodenal disease often involves antral inflammation, altered gastrin signalling, and increased acid delivery to the duodenum. Gastric ulcers more often reflect impaired local defence or direct injury, although H. pylori and NSAIDs can cause either gastric or duodenal ulceration. Location alone does not identify the cause. The two major causes may coexist. H. pylori weakens and inflames the mucosa, while NSAIDs suppress prostaglandin protection; together, the injury is more than additive,...