The medical term for the condition you have been experiencing is gastroesophageal reflux. Put simply, it means that acid produced by your stomach to help digest the food you eat is flowing backward, or refluxing, into your esophagus. Your esophagus is a tube about 10 inches long and one inch wide that leads from the back of your throat to your stomach. Acid washing back into your esophagus may cause irritation and heartburn.
At the base of your esophagus, between it and your stomach, is a muscular valve, or sphincter. This sphincter (lower esophageal Sphincter or LES) opens to let food into your stomach. Normally, it will not allow the contents of the stomach to back up into the esophagus. Sometimes, however, it doesn’t work properly or is overwhelmed for any number of reasons such as:
Changes in diet
Changes in lifestyle