Gastroesophageal reflux UMLS:C0017168 Gastro-oesophageal reflux Gastroesophageal reflux disease UMLS:C0018834 Heartburn Gastro-esophageal reflux Acid reflux Acid reflux disease A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter. GERD HP:0002020 GORD SNOMEDCT_US:16331000 SNOMEDCT_US:235595009 HP:0004793 SNOMEDCT_US:698065002 Abnormal esophagus physiology