A hiatal hernia occurs when weakened muscle tissue allows your stomach to bulge up through your diaphragm. It's not always clear why this happens, but pressure on your stomach and age-related changes in your diaphragm may contribute to the formation of a hiatal hernia.

How a hiatal hernia forms

Your diaphragm is a large, dome-shaped muscle that separates your chest cavity from your abdomen. Normally, your esophagus passes into your stomach through an opening in the diaphragm called the hiatus.

Hiatal hernias occur when the muscle tissue surrounding this opening becomes weak, and the upper part of your stomach bulges up through the diaphragm into your chest cavity.

Possible causes of hiatal hernia

Hiatal hernia could be caused by:

  • Injury to the area
  • Being born with an unusually large hiatus
  • Persistent and intense pressure on the surrounding muscles, such as when coughing, vomiting or straining during a bowel movement, or while lifting heavy objects
Feb. 03, 2015