Gastroesophageal reflux disease, commonly referred to as GERD, or acid reflux, is a condition in which the liquid content of the stomach regurgitates (backs up, or refluxes) into the esophagus. The liquid can inflame and damage the lining of the esophagus although this occurs in a minority of patients. The regurgitated liquid usually contains acid and pepsin that are produced by the stomach. (Pepsin is an enzyme that begins the digestion of proteins in the stomach.) The refluxed liquid also may contain bile that has backed-up into the stomach from the duodenum. (The duodenum is the first part of the small intestine that attaches to the stomach.) Acid is believed to be the most injurious component of the refluxed liquid. Pepsin and bile also may injure the esophagus, but their role in the production of esophageal inflammation and damage (esophagitis) is not as clear as the role of acid.

GERD is a chronic condition. Once it begins, it usually is life-long. If there is injury to the lining of the esophagus (esophagitis), this also is a chronic condition. Moreover, after the esophagus has healed with treatment and treatment is stopped, the injury will return in most patients within a few months.

Once treatment for GERD is begun, therefore, it usually will need to be continued indefinitely. Actually, the reflux of the stomach's liquid contents into the esophagus occurs in most normal individuals. In fact, one study found that reflux occurs as frequently in normal individuals as in patients with GERD. In patients with GERD, however, the refluxed liquid contains acid more often, and the acid remains in the esophagus longer.

As is often the case, the body has ways (mechanisms) to protect itself from the harmful effects of reflux and acid. For example, most reflux occurs during the day when individuals are upright. In the upright position, the refluxed liquid is more likely to flow back down into the stomach due to the effect of gravity. In addition, while individuals are awake, they repeatedly swallow, whether or not there is reflux. Each swallow carries any refluxed liquid back into the stomach.

Finally, the salivary glands in the mouth produce saliva, which contains bicarbonate. With each swallow, bicarbonate-containing saliva travels down the esophagus. The bicarbonate neutralizes the small amount of acid that remains in the esophagus after gravity and swallowing have removed most of the liquid.

Unfortunately, The most frequent symptoms of GERD are so common that they may not be associated with a disease and can be misdiagnosed. Self-diagnosis can lead to mistreatment. Consultation with a physician is essential to proper diagnosis and treatment of GERD.

GERD, affects at least an estimated 5% to 7% of the global population ? men, women, and children. (Prevalence based on once per day heartburn.) Heartburn and/or acid regurgitation experienced weekly has been found to occur in almost 20% of individuals.

Although common, GERD often is unrecognized ? its symptoms misunderstood. This is unfortunate because GERD is generally a treatable disease. Serious complications can result if it is not treated properly.

Persistent heartburn is the most frequent ? but not the only ? symptom of GERD. (The disease may be present even without apparent symptoms.) Heartburn is so common that it often is not associated with a serious disease, like GERD. All too often, GERD is either self- treated or mistreated.

GERD is a chronic disease. Treatment usually must be maintained on a long-term basis, even after symptoms have been brought under control. Issues of daily living, and compliance with long-term use of medication need to be addressed as well. This can be accomplished through follow-up, support, and education.