Hiatal hernia
The esophagus enters the abdominal cavity from the posterior mediastinum through a hole in the posterior diaphragm, which is called the esophageal hiatus. The gastric cardia and abdominal esophagus or abdominal viscera protrude into the chest cavity through this hiatus and its side, which is called hiatal hernia. Hiatal hernia is the most common type of diaphragmatic hernia, accounting for more than 90%. Hiatal hernia and reflux esophagitis can exist at the same time or separately. It is very important to recognize and distinguish between the two in clinical work.