A hiatal hernia, also known as diaphragmatic hernia, is a condition in which the upper part of the stomach bulges through an opening in the diaphragm. It is possible to have a hiatal hernia with no symptoms. But some people have heartburn related to gastroesophageal reflux disease, or GERD. Medicine can help relieve symptoms of hiatal hernias. Losing weight, not smoking and avoiding heavy meals can also help. If medicine and lifestyle changes do not work, surgical treatment is an option.