Reflux occurs when stomach acid leaks into the esophagus from the stomach. The esophagus is the tube that leads from the mouth into the stomach. It has 2 valves that help it work correctly. The lower valve is meant to keep acid in the stomach and the upper valve keeps acid out of the upper throat. If a little acid creeps up into the esophagus it may not cause heartburn because the lining of the esophagus is built to withstand it. If lots of acid gets past the valve it will cause heartburn. When only a little acid gets past both valves it may irritate the back of the voice box. The voice box cannot tolerate any acid so even a little can cause problems. This is called silent reflux and is very common. Some of the symptoms of silent reflux are dry cough, throat clearing, hoarseness and the sensation of a lump in the throat. Silent reflux may be treatable with simple dietary changes, elevating the head of the bed, weight loss or medication.