 [ Symptoms ] i had breast reduction my doctor took 550 g from right and 450g from left breast [ Disease ] heartburn is an irritation of the esophagus that is caused by stomach acid with gravity is 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 into the esophagus and cause a burning sensation occasional heartburn is not dangerous but chronic heartburn can indicate serious problems and can develop into gastroesophageal reflux disease gerd heartburn is a daily occurrence for about 10 of americans and up to 50 of pregnant women it is an occasional nuisance for 30 of the population