ACIDITY OR ACID RE FLUX In a simple language, when the gate (sphincters’) of the entrance of food from esophagus to stomach does not closed and food during digestion (process when Hcl mixed with food) reflux out of the gate is called acid re flux. Long duration of same problem may lead to GERD. One common cause of acid reflux disease is a stomach abnormality called a hiatal hernia. Normally, the diaphragm helps keep acid in our stomach. But if you have a hiatal hernia, acid can move up into your esophagus and cause symptoms of acid reflux disease. Th ese are other common risk factors for acid reflux disease: Eating large meals or lying down right after a meal Being overweight or obese Eating a heavy meal and lying on your back or bending over at th...