Gastroesophageal reflux disease (GERD) is a condition in which reflux of the stomach contents into the oesophagus results in symptoms or, occasionally, complications. GERD can be classified as non-erosive reflux disease (NERD) or erosive reflux disease (ERD) based on the presence or absence of esophageal mucosal damage seen on endoscopy. ERD can manifest in a wide range of symptoms which can be subdivided into typical, atypical, and extraesophageal symptoms. Typical symptoms include heartburn and acid regurgitation which have high specificity but low sensitivity for GERD. Atypical symptoms such as epigastric pain, dyspepsia, nausea, bloating, and belching may be suggestive of GERD but may overlap with other conditions in the differential diagnosis. Lastly, there are various extraesophageal symptoms including chronic cough, asthma, laryngitis, and dental erosions. In a small but important minority, complications of peptic esophagitis may occur including esophageal strictures, Barrett's oesophagus, and rarely esophageal adenocarcinoma. Hiatus hernia is statistically associated with GERD, the presence of which is relevant to surgical treatment. The diagnosis is typically made by a combination of clinical symptoms, response to acid suppression, as well as objective testing with upper endoscopy and esophageal pH monitoring. GERD is a chronic disease that typically requires long term management in the form of lifestyle modification, medical therapy and, for a subset of patients, surgical therapy. The mainstay of treatment is acid suppression which can be achieved with several classes of medications including antacids, histamine-receptor antagonists (H2RAs), or proton-pump inhibitors (PPIs).