Gastroesophageal reflux disease (GERD) is a more serious form of gastroesophageal reflux (GER), which is common. Gastroesophageal Reflux Disease is defined as chronic symptoms or mucosal damage produced by the abnormal reflux in the esophagus. GER is also called acid reflux or acid regurgitation, because digestive juices called acids rise up with the food. Gastroesophageal reflux disease, or GERD, affects at least an estimated 5% to 7% of the global population – men, women, and children. The main symptom of GERD in adults is frequent heartburn, also called acid indigestion.