What are heartburn, acid reflux and gastroesophageal reflux?

Heartburn is a burning sensation in the chest just like the word seems. It's usually right behind the breastbone. It usually occurs after meals, or sometimes at night. Acid reflux is where the juices from the stomach go the wrong way up into the esophagus. And GERD, the disease, is where you have those symptoms more than once or twice a week. Gastroesophageal reflux disease affects about 20% of Americans, it's pretty common.