A hernia occurs when part of an internal organ or body part protrudes through an opening into an area where it shouldn't. A hiatal hernia is named for the hiatus, an opening in the diaphragm between your chest and your stomach. Normally, the esophagus (the tube that carries food to the stomach) goes through this opening. In a hiatal hernia, part of the stomach and/or the section where the stomach joins the esophagus (called the gastroesophageal junction) slips through the hiatus into the chest.
There are two types of hiatal hernias:
Sliding — A part of the stomach and the gastroesophageal junction slip into the chest. Sliding hiatal hernias are common, especially in smokers, overweight people and women older than 50. These hernias are related to naturally occurring weaknesses in the tissues that normally anchor the gastroesophageal junction to the diaphragm and to activities or conditions that increase pressure within the abdomen. These activities or conditions include persistent or heavy coughing, vomiting, straining while defecating, sudden physical exertion and pregnancy.
Paraesophageal — The gastroesophageal junction remains in its proper place, and a fold of the stomach slips into the chest, pinched between the gastroesophageal junction and the diaphragm. Of the two types of hiatal hernias, paraesophageal hernias are more likely to cause severe symptoms.