GERD (Gastroesophageal Reflux Disease) is a chronic digestive disorder in which stomach acid or bile flows back into the esophagus, irritating its lining. This backflow, or reflux, often causes symptoms like heartburn, regurgitation, and chest discomfort and may lead to complications, including esophageal damage, if untreated. GERD management typically involves lifestyle changes, medications, or, in severe cases, surgery.