What is the MCC of gastritis/PUD?

• A. Chronic NSAIDS
• B. ETOH abuse
• C. Stress
• D. H. pylori infection

Answer: (D)

The key idea here is that infection with Helicobacter pylori is the most common cause of gastritis and peptic ulcer disease. H. pylori colonizes the stomach lining and produces urease, which converts urea to ammonia to neutralize nearby acid. This allows the bacteria to survive in the harsh gastric environment and triggers a chronic inflammatory response in the mucosa. Over time, this inflammation weakens the protective mucus layer and damages the gastric and/or duodenal mucosa, leading to gastritis and ulcers.

While NSAID use is a major cause of ulcers—through inhibition of prostaglandin synthesis and consequent reduction in mucosal defenses—it is not the single most common cause overall. Stress-related ulcers and alcohol can contribute to mucosal injury, but they’re not the primary drivers in most cases.