This is a summary. To read the whole story subscribe to BostonGlobe.com
Q: What’s the difference between heartburn and GERD?
A: Heartburn is the pain that results from acid reflux — when acidic contents in the stomach make their way back up to the esophagus. Normally, a sphincter muscle prevents acid from traveling backwards, but when acid gets through it can irritate the lining of the esophagus, causing a burning sensation in the chest.