Acid reflux is one of the most common acute upper gastrointestinal problems in adults of all ages. It often arises as an isolated incident after overeating, vigorous physical activity after a heavy meal and with excessive alcohol consumption. In most of these instances it is not a cause for concern and over-the-counter antacids are sufficient to ease the burning chest pain commonly referred to as heartburn. Sometimes this reflux may be recurrent, may occur spontaneously and trouble a person over months or years. In these instances it is is known as gastroesophageal reflux disease (GERD). While GERD also technically refers to acute episodes of acid reflux as well, the term GERD generally infers a more chronic state.
In order to understand GERD, it is important to have at least a basic knowledge of human anatomy. Food and drink pass from the mouth to the throat (pharynx), down the food pipe (esophagus) and into the stomach. At the junction of the esophagus and stomach is a muscular lower esophageal sphincter (LES) that controls the passage of food into the stomach. It is usually contracted and prevents the back flow of stomach acid up into the esophagus and opens momentarily when eating to allow food to enter the stomach. While the stomach is able to withstand the corrosive effects of acid, the esophagus is not and the esophageal lining is easily damaged with the entry of acid. Fortunately the esophagus has certain defense mechanisms to counteract the effect of acid should it enter. Strong and repeated esophageal contractions push the acid back into the stomach oran excessive secretion of the naturally alkaline saliva passes into the esophagus and neutralizes the acid.
The exact cause of gastroesophageal reflux disease cannot always be ascertained but it is known to be due to one of more of the following defective mechanisms :
GERD is more likely to be aggravated with :
However, these risk factors do not actually cause one or more of the defective mechanisms mentioned above but instead make it worse.
GERD becomes more common with age and the prevalence rises significant after the age of 40 years. Many of the mechanical defects that allow stomach acid to flow backwards into the esophagus are more likely to occur or be exacerbated in the elderly. This is due to several reasons such as :