Heartburn is a painful burning sensation in the esophagus, just below or behind the breastbone. The pain often rises in your chest and may radiate to your neck or throat. Almost everyone has occasional heartburn. If you have frequent, ongoing heartburn, you may have gastroesophageal reflux disease (GERD).
Normally, when food or liquid enters your stomach, a band of muscle at the end of your esophagus (called the lower esophageal sphincter or LES) closes off the esophagus. If this muscle fails to close tightly enough, stomach contents can back up (reflux) into the esophagus. This partially digested material is usually acidic and can irritate the esophagus, causing heartburn and other symptoms.
