What Causes GERD?

GERD, or gastroesophageal reflux disease, is caused by the weakening of the lower esophageal sphincter (LES). The LES is a ring of muscle that acts as a valve between the esophagus and the stomach, allowing food and liquids to enter the stomach while preventing them from flowing back up into the esophagus. When the LES is weakened or relaxed, stomach acid can flow back up into the esophagus, causing irritation and inflammation. Other factors that can contribute to the development of GERD include obesity, pregnancy, smoking, certain medications, and a hiatal hernia.