Causes

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 a hiatal hernia might be caused by:

• Age-related changes in your diaphragm
• Injury to the area, for example, after trauma or certain types of surgery
• Being born with an unusually large hiatus
• Persistent and intense pressure on the surrounding muscles, such as while coughing, vomiting, straining during a bowel movement, exercising or lifting heavy objects