Acid reflux, also recognized as heartburn, is a root symptom of gastroesophageal reflux disease (GERD). GERD is a condition in some patients whereby the ring muscle at the end of the gullet becomes loose.
This muscle is known as the lower esophageal sphincter, or LES. The LES is supposed to separate stomach acid from creeping up the gullet during digestion. When the LES loosens and does not close, you get a reflux and will feel its burning effects.
Occasional reflux usually isn’t something to worry about. Over more than 50 million Americans experience a heartburn once a month. However, if you get them way too often, you might have to check for a GERD condition.