Gastroesophageal reflux disease is the reflux of duodenal contents into the esophagus causing symptoms such as heartburn, reflux esophagitis, and damage to adjacent tissues of the esophagus such as the pharyngeal airway. The main pathogenesis is the result of a weakened anti-reflux defense mechanism and an attack on the esophageal mucosa by the refluxed material. The main factors affecting the function of the gastroesophageal junction include: the pressure of the lower sphincter, the angle of the cardia-esophageal junction, and the action of the diaphragm. Symptoms, signs and complications Heartburn with or without reflux of gastric contents into the oral cavity is the most prominent symptom. Atypical symptoms may include non-cardiac chest and back pain, dysphagia, pharyngitis, chronic cough, and asthma. Complications include esophagitis, upper gastrointestinal bleeding, esophageal stricture and Barrett’s esophagus. Digestive strictures may present with progressive dysphagia to solid foods. Diagnosis A thorough history is useful for diagnosis. x-ray, endoscopy, esophageal manometry, pH monitoring and Bernstein’s acid instillation test help to clarify the diagnosis and reveal possible complications (e.g. Barrett’s esophagus). Esophageal manometry measures pressure at the lower esophageal sphincter and shows its strength, thus allowing differentiation between a normal and an atretic sphincter. Esophageal pH monitoring provides direct evidence of GERD. the Bern-stein test is strongly associated with the presence of symptomatic GERD, and acid instillation can lead to rapid onset of symptoms. Esophageal biopsy shows thinning of the squamous mucosal layer and proliferation of basal cells. These histological changes are seen in patients with endoscopic esophagitis not visible to the naked eye. Treatment of uncomplicated GERD includes: (1) elevation of the head of the bed by approximately 15 cm; (2) avoidance of strong stimulants that cause acid secretion (e.g., too sweet, spicy, coffee, alcohol, etc.); (3) avoidance of certain medications (e.g., anticholinergics), smoking, because these factors can decrease lower esophageal sphincter pressure; (4) administration of acid-suppressants to neutralize gastric acid; (5) application of H2 blockers to reduce the acidity of gastric juice (sometimes combined with other drugs); (6) application of proton pump inhibitors omeprazole and lansoprazole for 4 to 8 weeks; (7) anti-reflux surgery, i.e. fundoplication. (8) Treatment of complications.