THE FACTS For people with chronic heartburn, restful sleep is no easy feat. Fall asleep in the wrong position, and acid slips into the esophagus, a recipe for agita and insomnia.

Doctors recommend sleeping on an incline, which allows gravity to keep the stomach’s contents where they belong. But sleeping on your side can also make a difference  so long as you choose the correct side. Several studies have found that sleeping on the right side aggravates heartburn; sleeping on the left tends to calm it.

The reason is not entirely clear. One hypothesis holds that right-side sleeping relaxes the lower esophageal sphincter, between the stomach and the esophagus. Another holds that left-side sleeping keeps the junction between stomach and esophagus above the level of gastric acid.

Image Credit... Christoph Niemann

In a study in The Journal of Clinical Gastroenterology, scientists recruited a group of healthy subjects and fed them high-fat meals on different days to induce heartburn. Immediately after the meals, the subjects spent four hours lying on one side or the other as devices measured their esophageal acidity. Ultimately, the researchers found that “the total amount of reflux time was significantly greater” when the subjects lay on their right side.