Final answer:
The two types of hiatal hernias are Sliding and Paraesophageal, with Sliding being more common. Sliding hernias involve the stomach sliding upwards, while Paraesophageal hernias can be associated with gastric twisting but are less common.
Step-by-step explanation:
The two types of hiatal hernias are Sliding and Paraesophageal hernias. The more common type is the Sliding hiatal hernia, where the stomach and the section of the esophagus that joins the stomach slide up into the chest through the hiatus. In contrast, the Paraesophageal hernia, which is less common, occurs when part of the stomach squeezes through the hiatus, lying next to the esophagus without displacing the esophagus. One critical difference between them is that the Paraesophageal hernia is associated with the potential for gastric twisting, while the Sliding hernia is not.