What Causes Heartburn/GERD?

The food you swallow travels from your mouth to your stomach through a hollow tube doctors call the esophagus (the food pipe). Before entering the stomach, food must pass through a tight muscle at the lower part of your esophagus called the lower esophageal sphincter (LES). The LES prevents food from traveling backward into the esophagus.

Once in the stomach, stomach acid digests your food. This acid is very strong and can damage most parts of the body. Fortunately, your stomach is protected from its own acid by a special mucous layer. Your esophagus, however, does not have any such special protection. If your LES does not close completely, the lower part of your esophagus can be damaged by stomach acid. When this happens, you may experience heartburn.

Conditions such as hiatal hernia, pregnancy, or diabetes may predispose individuals to reflux disease. Infants, particularly premature infants, commonly experience reflux disease.