Heartburn is a burning feeling in the middle of your chest caused by acid leaking upwards from the stomach into the esophagus, or swallowing tube. Doctors call this reflux esophagitis. Normally, the muscular esophagus acts like a one-way valve allowing food to enter your stomach after swallowing, but not letting anything go back up. When your esophagus is too loose where it connects to the stomach...
