A figure with visible gastrointestinal tract is shown to compare a healthy esophagus and an inflamed esophagus due to erosion by stomach acid in a condition known as gastroesophageal reflux disease (GERD). GERD is a disorder in which the sphincter muscle at the base of the esophagus relaxes at the wrong time, causing stomach acid to flow backwards into the esophagus. The acid irritates and inflames the lining of the esophagus, causing a burning sensation. Changes in diet and lifestyle can help reduce or eliminate symptoms of GERD and also lower the risk of developing the disease in the first place.