Overview

A hiatal hernia occurs when the upper part of your stomach bulges through the large muscle separating your abdomen and chest (diaphragm).

Your diaphragm has a small opening (hiatus) through which your food tube (esophagus) passes before connecting to your stomach. In a hiatal hernia, the stomach pushes up through that opening and into your chest.

A small hiatal hernia usually doesn't cause problems. You may never know you have one unless your doctor discovers it when checking for another condition.

But a large hiatal hernia can allow food and acid to back up into your esophagus, leading to heartburn. Self-care measures or medications can usually relieve these symptoms. A very large hiatal hernia might require surgery.

Symptoms

Most small hiatal hernias cause no signs or symptoms. But larger hiatal hernias can cause:

  • Heartburn
  • Regurgitation of food or liquids into the mouth
  • Backflow of stomach acid into the esophagus (acid reflux)
  • Difficulty swallowing
  • Chest or abdominal pain
  • Shortness of breath
  • Vomiting of blood or passing of black stools, which may indicate gastrointestinal bleeding

When to see a doctor

See your doctor if you have any persistent signs or symptoms that worry you.

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

Risk factors

Hiatal hernia is most common in people who are:

  • Age 50 or older
  • Obese