Gastroesophageal reflux disease
Gastroesophageal reflux disease (GERD), gastro-oesophageal reflux disease (GORD), gastric reflux disease, or acid reflux disease is defined as chronic symptoms or mucosal damage produced by the abnormal reflux of stomach acid to the esophagus. A typical symptom is heartburn.
This is commonly due to transient or permanent changes in the barrier between the esophagus and the stomach. This can be due to incompetence of the lower esophageal sphincter, transient lower esophageal sphincter relaxation, impaired expulsion of gastric reflux from the esophagus, or a hiatal hernia.
A different type of acid reflux which produces respiratory and laryngeal manifestations is laryngopharyngeal reflux (LPR), also called extraesophageal reflux disease (EERD). Unlike GERD, LPR is unlikely to produce heartburn, and is thus sometimes called silent reflux.