Hiatal hernias can be divided into two main types: sliding and paraoesophageal. 

In a sliding hiatal hernia, the stomach and the section of the oesophagus that joins the stomach slide up into the chest through the hiatus, while in a paraesophageal hiatal hernia, the oesophagogastric junction is located at or below the level of diaphragmatic hiatus and part of the stomach alongside the oesophagus (> 2 cm), above the diaphragm.

In a mixed, sliding, and paraesophageal hiatal hernia, the esophagogastric junction and stomach are located above the diaphragm and 2 cm or more of the fundus is located cephalad to the lower esophageal sphincter and esophagus. Hiatal hernias can be identified by an air-fluid level.