If you have heartburn or regurgitation at least twice a week for multiple weeks, then your symptoms fit the typical definition of acid reflux disease. This condition is one of the most common diseases on the planet among adults, with a prevalence in the United States and Europe of 10 to 20 percent of the population, according to a study published in the June 2014 issue of Gut. Acid reflux is a miserable disease, not only profoundly affecting quality of life, but also causing a huge economic burden. The cost of the diagnosis and treatment is colossal — to the tune of about $40 billion annually.
There are two basic types of acid reflux disease: gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux disease (LPRD). As the name suggests, the main source of the problem with acid reflux disease is stomach acid. The primary difference between the two types is the location in which the acid travels, either up to the esophagus (GERD) or further up to the throat (LPRD).
Gastroesophageal Reflux Disease (GERD)
Breaking down the term into its individual parts helps explain what GERD means and what the disease is. “Gastro” refers to the stomach. Normally, food that is swallowed reaches the stomach, where it is broken down by acid and enzymes — such as pepsin — produced by the lining of the stomach. “Esophageal” refers to the esophagus, which is the organ connecting the throat to the stomach. It’s like a highway for food. “Reflux” comes from the Latin words “re” (meaning back, again) and “fluxus” (meaning flowing). So reflux literally means backflow, or reversal of flow. GERD thus describes a condition exhibited by reversal of the flow of stomach contents back up into the esophagus.
Laryngopharyngeal Reflux Disease (LPRD)
When acid reflux goes further than only the esophagus, it is called laryngopharyngeal reflux. To fully comprehend just how far beyond the esophagus the acid may travel, a basic understanding of the structures surrounding the top of the esophagus is necessary.
The throat — also known as the pharynx — is the common pathway for food and air. At its lower end, the pharynx divides into the larynx in front and the esophagus in back. The voice box, or larynx, is a tube-like structure containing the vocal cords. Air passes through the larynx to enter the windpipe, or trachea, on its way to the lungs. The top part of the esophagus sits immediately behind the larynx, and as the esophagus travels down the chest, it is sandwiched between the spine in back and the trachea in front.
As the throat is connected to many other body areas, acid that travels to the throat can spill over into various areas. It can ultimately affect not only the larynx, but also the lungs, teeth, sinuses and even ears. While LPRD is not as common as GERD, it is probably more frequent than people think, as it is likely underdiagnosed. LPRD also tends to be influenced by other factors in addition to acid traveling from the stomach. The inflammation caused by LPRD is made worse by pepsin accompanying the acid refluxed from the stomach as well as the acid in certain foods and drinks as they travel on their way down to the stomach.