A condition in which part of the stomach pushes up through the diaphragm muscle.
In hiatal hernia, part of the stomach pushes through the diaphragm muscle into the chest cavity. It enters via an opening where the food tube (esophagus) passes on its way to the stomach.
Most small hiatal hernias have no symptoms and don't cause problems.
A large one may cause heartburn and need treatment with drugs or surgical repair.