The pathogenesis of cough in gastroesophageal reflux disease

The primary event in gastroesophageal reflux (GER) is the movement of acid, pepsin, and other noxious substances from the stomach into the esophagus (1). In healthy individuals, reflux is a normal, mostly asymptomatic event. Gastroesophageal reflux disease (GERD) is defined as occurring when reflux leads to symptoms or physical complications. In most patients this occurs when there is excessive exposure of the distal esophageal mucosa to refluxed gastric contents resulting in heartburn, epigastric or retrosternal discomfort, and chest pain (2). Prolonged exposure can lead to esophagitis, esophageal ulceration and its complications such as bleeding or stricture formation. However, esophageal reflux symptoms can also occur without esophagitis, and there can be significant reflux without classical symptoms (3).