This article is from the Big Folks Health FAQ, by firstname.lastname@example.org (Sharon Curtis) with numerous contributions by others.
A hiatal hernia can be 2 types, sliding or paraesophageal.
Sliding is more common. In obese persons, especially older persons,
the hiatal area is more relaxed and stretched. A piece of the
esophageal junction (part of the esophagus) slides up
over the diaphragm with a portion of the stomach. The sphinter that
closes off your esophagus functions poorly, and gastric juices
reflux (back up) and causes heartburn. This gastric juice reflux
leads to esophagitis (swelling and inflammation) and can cause a
stricture or narrowing as scarring takes place.
Early treatment includes a bland diet, antacids, weight reduction,
and sleeping in a semi-sitting position to control reflux. More
drastic treatment for severe cases include surgery to repair the
esophageal junction and replace it below the diaphragm.