How does a hiatal hernia relate to acid reflux?

Here are some ...: Hiatal hernia may un-duely lax the sphincter between esophagus and stomach at times, in turn leading to unwanted backflow of gastric content into the esophagus. More? Ask Doc timely.

Unclear : Many people with large hiatal hernias have no reflux, and many with reflux have no hiatal hernia. Reflux is probably mostly a functional problem related to excessive random openings of the valve between the stomach and esophagus called transient lower esophageal sphincter relaxations. Hope this helps!