What causes Heartburn?
Almost everyone has heartburn sometimes. If you have heartburn very often, 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 closes off the esophagus. This band is called the lower esophageal sphincter (LES). If this band does not close tightly enough, contents from the stomach can back up (reflux) into the esophagus. This partly digested material can irritate the esophagus, causing heartburn and other symptoms.
Heartburn is more likely if you have a hiatal hernia. A hiatal hernia is when the top part of the stomach sticks up into the chest cavity. This weakens the LES and makes it easier for acid to back up from the stomach into the esophagus.
Pregnancy and many medications can bring on heartburn or make it worse. </s>