Gastroesophageal Reflux Disease (GERD) is a condition wherein the chyme (the semi-digested food in the stomach) goes up in to the esophagus which is primarily caused by dysfunctional lower esophageal sphincters (LES), abnormal contractions of the esophagus, and delayed emptying of the stomach.
Esophagitis, or inflammation of the lining of the esophagus, may result from GERD. This is primarily due to the reflux of acid from the stomach to the esophagus. Repeated acid reflux would normally irritate the esophagus since the pH of this acid is low enough to cause redness, swelling, warmth, pain, and loss of function (collectively known as inflammation) to the esophagus.
Heartburn results from the reflux of acid due to a dysfunctional LES. It is called a heartburn not because the actual heart burns, but because it imitates the symptoms of a heart attack since the esophagus is just near the heart. Once the acid goes up in to the esophagus, it produces a burning sensation in the chest which usually occurs after meals.
Nausea or the urge to vomit also occurs in GERD since the reflux of chyme from the stomach stimulates the esophagus to push the chyme back up to the mouth.
Regurgitation of chyme or vomiting of undigested food also occurs in GERD which is also due to dysfunctional LES. This, in turn, produces an acid taste in the mouth.
Untreated GERD could cause esophageal ulcers primarily due to the continuous irritation of the esophagus caused by acid reflux. This results to bleeding of the esophagus. If bleeding is not corrected, it can cause shock and death. Esophageal bleeding would lead to hematemesis, or blood in the vomitus, and melena, or dark, tarry stool. Untreated esophageal ulcers will also lead to esophageal perforation, which also results to shock and death if left untreated.
Barrett’s Esophagus can also occur in GERD. This is primarily due to the repeated injury of the esophageal lining caused by acid reflux, which causes metaplasia of the lining. This, however, is said to be a defense mechanism of the esophagus since it will become more resistant to injuries.
The repeated reflux of acid to the esophagus would cause spasm of the larynx resulting to dyspnea and cough. Sometimes, severe acid reflux could also cause aspiration pneumonia due to aspiration of the vomitus which causes lung damage. There are a few instances wherein the presenting manifestation of GERD is cough, rather than the heartburn.