Gastroesophageal reflux disease (GERD), gastro-oesophageal reflux disease (GORD), gastric reflux disease, or acid reflux disease is a chronic symptom of mucosal damage caused by stomach acid coming up from thestomach into the esophagus.^[1]

GERD is usually caused by changes in the barrier between the stomach and the esophagus, including abnormal relaxation of the lower esophageal sphincter, which normally holds the top of the stomach closed, impaired expulsion of gastric reflux from the esophagus, or a hiatal hernia. These changes may be permanent or temporary.

Treatment is typically via lifestyle changes and medications such as proton pump inhibitors, H₂ receptor blockers or antacids with or without alginic acid.^[2] Surgery may be an option in those who do not improve. In the Western world between 10 and 20% of the population is affected.