Whenever a part of the internal body moves into a place where it shouldn’t be or doesn’t belong, the medical community refers to this condition as hernia. The hiatus is an opening that is located towards the bottom of the diaphragm, which is the muscular wall responsible for separating the abdomen from the chest cavity. Normally, the pipe that moves your food into your stomach goes through the hiatus into the stomach. However, in the case of a hiatal hernia, the stomach pushes into the chest through the available opening.