When acids from the stomach flow back into the throat and mouth through the oesophagus (the tube that connects the throat to the stomach inside our body), giving a sour taste in the mouth, it is called acid reflux. The acid irritates the walls of the oesophagus causing a burning sensation in the chest and throat (heartburn). Others patients with GERD may experience difficulty in swallowing and a persistent dry cough. Having acid reflux because of eating certain foods and indigestion once in a while may be normal, but regular bouts that go untreated may lead to other serious problems like ulcers and damage to the lining of the oesophagus.