The core issue is retrograde flow of gastric contents (acid, pepsin, bile) into the esophagus, leading to mucosal erosion. Key mechanisms include: Reduced lower-esophageal-sphincter (LES) pressure or frequent transient LES relaxations (TLESRs) that disable the anti-reflux barrier Hiatus hernia, which weakens the diaphragmatic crus and creates an acid pocket Impaired esophageal clearance (weak peristalsis, reduced saliva) that prolongs acid exposure A damaged mucosal barrier (widened intercellular spaces, thinner mucus layer) lowering resistance to aggressive factors Obesity, pregnancy, late-night meals, high-fat diet, smoking, alcohol and drugs such as aspirin raise intra-abdominal pressure or directly relax the sphincter, aggravating reflux. Chronic reflux... Learn more