Normal Function of the Esophagus
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The esophagus seems to have only one important function in the body—to carry food, liquids, and saliva from the mouth to the stomach. The stomach then acts as a container to start digestion and pump food and liquids into the intestines in a controlled process. Food can then be properly digested over time, and nutrients can be absorbed by the intestines.
The esophagus transports food to the stomach by coordinated contractions of its muscular lining. This process is automatic and people are usually not aware of it. Many people have felt their esophagus when they swallow something too large, try to eat too quickly, or drink very hot or very cold liquids. They then feel the movement of the food or drink down the esophagus into the stomach, which may be an uncomfortable sensation.
The muscular layers of the esophagus are normally pinched together at both the upper and lower ends by muscles called sphincters. When a person swallows, the sphincters relax automatically to allow food or drink to pass from the mouth into the stomach. The muscles then close rapidly to prevent the swallowed food or drink from leaking out of the stomach back into the esophagus or into the mouth. These sphincters make it possible to swallow while lying down or even upside-down.
When people belch to release swallowed air or gas from carbonated beverages, the sphincters relax and small amounts of food or drink may come back up briefly; this condition is called reflux. The esophagus quickly squeezes the material back into the stomach. This amount of reflux and the reaction to it by the esophagus are considered normal.
While these functions of the esophagus are obviously an important part of everyday life, people who must have their esophagus removed, for example because of cancer, can live a relatively healthy life without it.
Gastroesophageal Reflux Disease (GERD)
The stomach produces acid and enzymes to digest food. When this mixture refluxes into the esophagus more frequently than normal, or for a longer period of time than normal, it may produce symptoms. These symptoms, often called acid reflux, are usually described by people as heartburn, indigestion or "gas." The symptoms typically consist of a burning sensation below and behind the lower part of the breastbone or sternum.
Having occasional liquid or gas reflux is considered normal. When it happens frequently, particularly when not trying to belch and causes other symptoms, it is considered a medical problem or disease. However, it is not necessarily a serious one that requires seeing a physician.
Almost everyone has experienced these symptoms at least once, typically after overeating. GERD symptoms can also result from being overweight, eating certain types of foods, or being pregnant.
Overall, more than 60 million American adults experience GERD, making it one of the most common medical conditions. In most people, GERD symptoms last only a short time and require no treatment at all. More persistent symptoms are often quickly relieved by over-the-counter acid-reducing agents such as antacids. Other drugs used to relieve GERD symptoms are antisecretory drugs such as histamine2 (H2) blockers or proton pump inhibitors.
People who have GERD symptoms frequently should consult a physician. Other diseases can have similar symptoms, and prescription medications in combination with other measures might be needed to reduce reflux. GERD that is untreated over a long period of time can lead to complications, such as an ulcer in the esophagus that could cause bleeding. Another common complication is scar tissue that blocks the movement of swallowed food and drink through the esophagus; this condition is called stricture.
Esophageal reflux may also cause certain less common symptoms, such as hoarseness or chronic cough, and sometimes provokes conditions, such as asthma. While most patients find that lifestyle modifications and acid-blocking drugs relieve their symptoms, other more permanent treatment options are available that can cure GERD. These options can be performed without incisions or sometimes with minimally invasive surgery.