Reflux is the back flow of stomach contents through the esophagus. There are two types of reflux:
1. Gastro-Esophageal Reflux Disease (GERD) occurs when contents from the stomach return to the esophagus. This causes swelling and irritation to the tissue of the esophagus. Symptoms include "heartburn" or indigestion.
2. Laryngo-Pharyngeal Reflux Disease (LPRD) occurs when stomach contents travel all the way up through the top sphincter of the esophagus to the tissues in the throat.