Priyanka Chugh, MD, is board-certified gastroenterologist with a background in internal medicine. She practices with Trinity Health of New England in Waterbury, Connecticut.
A hiatal hernia occurs when the upper part of your stomach bulges through an opening in your diaphragm—a muscle that separates the chest and abdomen. The opening is called the esophageal hiatus, and it’s where your esophagus (food tube) passes through before it reaches the stomach.
As the stomach presses up, it can sometimes allow foods and acids of the stomach to backflow into the esophagus. Symptoms may include heartburn, abdominal discomfort, throat irritation, belching, and regurgitation.
The majority of hiatal hernias are small and do not cause symptoms or require treatment. In rare cases, there can be complications that are medical emergencies and require surgery.
A hiatal hernia happens due to a weakening of the diaphragm muscles. In most cases, the cause of this weakening is unclear, but risk factors include aging, traumatic injury, and abdominal surgery. The hiatal hernia can also be congenital (present at birth) or develop in those who have an abnormally large hiatus.
Most hiatal hernias do not cause symptoms and you may only know you have one if it is discovered in an X-ray or other imaging test. A hiatal hernia can shift the positioning of the lower esophageal sphincter (LES) valve and lead to reflux with related heartburn, regurgitation, burping or hiccuping after eating, irritated throat, sour or bitter taste in the mouth, and bad breath.
If the hernia strangles the blood supply to the stomach, it is a medical emergency that requires urgent medical attention. Symptoms of this complication can include severe chest pain, shortness of breath, fever, fatigue, bloating, vomiting, inability to pass gas, constipation, warmth or redness over the herniation, rapid heart rate, and bloody or tarry stools.
The diaphragm, also known as the thoracic diaphragm, is the main muscle involved in breathing. It is a dome-shaped muscle that separates the chest and the abdomen. The diaphragm moves rhythmically while remaining anchored to the ribs, sternum, and spine. When the diaphragm contracts, it opens the lungs.
An irritation or inflammation of the esophagus that happens when stomach acid comes into contact with the lining of the esophagus. It can cause a burning sensation and pain. Chronic heartburn may indicate a digestive disorder, such as gastroesophageal reflux disease (GERD).
A hernia occurs when an organ presses through weak areas of muscle that surround it. This happens most commonly in the abdomen, chest, or groin, and involves the stomach or intestines. Sometimes there is a visible bulge under the skin.
An opening or passage in an anatomical part or organ. The diaphragm has an esophageal hiatus (where the esophagus passes), an aortic hiatus (where the aorta passes), and a cavus hiatus (where the inferior vena cava passes).
Explore an interactive model that shows how and where a hiatal hernia occurs, along with what it can look like when the stomach pushes into the esophageal hiatus.
Cleveland Clinic. Hiatal hernia. Updated January 9, 2020.
Hyun JJ, Bak YT. Clinical significance of hiatal hernia. Gut Liver. 2011;5(3):267-277. doi:10.5009/gnl.2011.5.3.267