Gastroesophageal Reflux Disease
What is GERD?
Gastroesophageal Reflux Disease (GERD) is a common ailment in the United States that affects up to 7percent of the population. GERD is the medical term for the movement of fluid and food from the stomach into the esophagus-reflux.
This reflux produces a variety of symptoms including heartburn, acid regurgitation, chest pain, hoarseness and chronic cough. The most common of these symptoms is heartburn, which, interestingly, has nothing to do with the heart. In the United States, 7 percent of people suffer from heartburn every day, 14 percent once per week and 35 to 44 percent once per month.
How does GERD happen?
GERD results from an imbalance in three factors:
- The swallowing force in the esophagus
- The integrity of the valve mechanism at the junction of the stomach and the esophagus
- The pressure in the stomach and abdomen
Normally, pressure in the chest is less than that in the abdomen; that's how we breathe. When we take a deep breath, we expand our chest cavity and contract our diaphragm. That lowers the pressure in our chest below the atmospheric pressure and air comes into our lungs.
At high altitudes, atmospheric pressure is lower and, therefore, it is harder to breathe. Pressure in the chest decreases at the same time the pressure in the abdomen increases. The greater intra-abdominal pressure results in a tendency for liquids and foods to regurgitate or move from the stomach into the low pressure, intra-thoracic esophagus. This is especially noticeable when we lie down and the force of gravity that helps keep liquids and food in the stomach is not present. A suction is created in which each breath causes pressure in the chest to lower, and fluid in the stomach to be pulled into the esophagus. Under normal circumstances, the lower esophageal sphincter at the junction of the esophagus and stomach, is a high pressure zone that creates a valve-like mechanism and prevents reflux. If that valve does not work, reflux occurs.
What is the lower esophageal sphincter (LES)?
The LES is an area of esophageal muscle at the end of the esophagus that normally contracts and closes off the esophageal lumen. When we swallow, the upper esophagus contracts and the LES relaxes, allowing the passage of food, liquid and/or saliva into the stomach.
Does GERD always result from a non-functioning LES?
No. GERD can also result from impaired swallowing or from too high a pressure in the stomach, as might occur when the stomach is blocked from an ulcer or when it doesn't empty properly. Furthermore, the LES has a normal pressure in about 60% of patients with GERD, but relaxes inappropriately (transient inappropriate LES relaxation). If the LES relaxes when it should not, reflux of stomach contents into the esophagus results. This commonly occurs at night.
What happens if GERD is left untreated for a long period of time?
Untreated GERD can result in numerous problems that are viewed as complications of the disorder.
- Reflux esophagitis (inflammation)
- Stricture (narrowing) of the esophagus resulting in difficulty swallowing (dysphagia)
- Recurrent pneumonia
- Barrett's esophagus and esophageal cancer