What exactly is heartburn?
It has nothing to do with your heart, so why call it heartburn? Probably because it’s easier than saying “esophageal burn.” Heartburn happens when acid escapes from your stomach up into your esophagus. Your lower esophageal sphincter is supposed to prevent that. But sometimes it relaxes or doesn’t close properly and the acid escapes. Unlike the stomach, the esophagus isn’t meant to house acid, so that’s when you feel the burn.