Gastroesophageal reflux disease (GERD), gastro-oesophageal reflux disease (GORD), gastric reflux disease, acid reflux disease, or reflux (in babies and young children) is a chronic condition of mucosal damage caused by stomach acid coming up from the stomach into the esophagus (chronic ). Occasional reflux causes heartburn, but chronic reflux leads to reflux esophagitis, GERD, and sometimes Barrett esophagus.