Gastroesophageal reflux disease (GERD)

Also known as: GERD, Heartburn, Acid reflux, Acid indigestion

Gastroesophageal reflux disease, or GERD, is a digestive disorder that occurs when gastric acid from the stomach flows back up into the food pipe or esophagus. Heartburn is the most common symptom of GERD.

A muscle at the bottom of the esophagus opens to let food in and closes to keep food in the stomach. This muscle is called the lower esophageal sphincter (LES). When the LES relaxes too often or too long, acid backs up into the esophagus and causes heartburn.