despite its name heartburn has nothing to do with the heart. (some of the symptoms however are similar to those of a heart attack or heart disease. ) heartburn is an irritation of the esophagus that is caused by stomach acid and is a common part of pregnancy. with gravity's help a muscular valve called the lower esophageal sphincter or les keeps stomach acid in the stomach. the les is located where the esophagus meets the stomach -- below the rib cage and slightly left of center. normally it opens to allow food into the stomach or to permit belching; then it closes again. but if the les opens too often or does not close tight enough stomach acid can reflux or seep back into the esophagus and cause a burning sensation. occasional heartburn isn't dangerous but chronic heartburn can indicate serious problems such as gastritis and can develop into gastroesophageal reflux disease or gerd. heartburn is a daily occurrence for 10% of americans and 50% of pregnant women. it's an occasional nuisance for another 30% of the population.
what is heartburn?