GERD, gastroesophageal reflux disease, is caused when stomach acid travels back up into the esophagus. The symptoms of GERD are frequent heartburn, difficulty swallowing, regurgitation of food and fluids, chest pain and asthma. Normally, there is a valve (LES) at the lower portion of your esophagus that opens when you swallow but remains closed at all other times. This valve usually prevents reflux. Malfunction of this valve causes reflux. GERD may be controlled with lifestyle and diet changes. Not all heartburn is GERD, but longstanding heartburn, especially if uncontrolled with over the counter medications, weight control and lifestyle changes, may require evaluation by gastroenterologist.