A hiatal hernia occurs when the stomach protrudes through the opening in the diaphragm. It is a very common finding and occurs in approximately half the adult population of the United States. There are two types of hiatal hernia. The most common form is a sliding hiatal hernia. Far less common is a variety called a paraesophageal hiatal hernia. The paraesophageal variety may be associated with complications such as bleeding. This type of hiatal hernia is not particularly a problem of elderly patients.