Got a burning feeling in your upper chest after a meal? If you’re thinking it’s acid reflux (sometimes referred to by the name of its main symptom, heartburn), you’re probably right. “Heartburn is the manifestation — the symptom — of acid reflux, which is when stomach contents come back up your esophagus,” says Matilda Hagan, MD, a gastroenterologist and the associate director of the Center for Inflammatory Bowel and Colorectal Diseases at Mercy Medical Center in Baltimore. [1] You can often pinpoint a reason for the burn (that five-alarm chili, perhaps? ), but if you’re having heartburn at least twice a week for more than a few weeks, it could be a symptom of a more serious condition called gastroesophageal reflux disease (GERD)While it may seem that GERD is just a fancy name for acid reflux, they are more like close cousins than identical twins.