GERD (short for Gastroesophageal Reflux Disease) happens when food and stomach juice—more sour than a lemon!—travel back up into the esophagus, the tube that connects your mouth to your stomach.

It is kind of like when you press a balloon filled with water, and the water sloshes up and down.

GERD can cause more hiccups than usual, belly aches, nausea, throwing up, and a hot, burning feeling in your chest called heartburn.