Gastro-Esophageal Reflux Disease (GERD). A common relapsing condition affecting approximately 10% of the U.S. population and caused by an abnormal exposure of the lower esophagus to refluxed gastric contents, causing irritation and injury to the esophageal tissues. GERD develops as a result of relaxations of the transient lower esophageal sphincter. Typical presenting symptoms are heartburn, an epigastric burning sensation and acid regurgitation. However, some patients may present with atypical symptoms such as chest pain, shortness of breath, wheezing, and coughing.