A hiatus hernia (also called a hiatal hernia) is a condition where part of the stomach pushes upward through the opening in the diaphragm that the esophagus normally passes through. About 20% of adults in the U.S. have one, and most never know it because it causes no symptoms. When it does cause problems, the most common issue is acid reflux.
How It Happens
Your diaphragm is a large dome-shaped muscle separating your chest from your abdomen. It has a small oval-shaped opening called the hiatus, which your esophagus (the tube connecting your mouth to your stomach) passes through on its way down. Normally, the stomach sits entirely below the diaphragm, and the hiatus fits snugly around the esophagus.
In a hiatus hernia, the opening stretches or weakens, and part of the stomach slides up through it into the chest cavity. Interestingly, a small amount of this happens naturally every time you swallow. The top of the stomach briefly pushes upward through the hiatus during normal swallowing, then slides back down. A hiatus hernia develops when part of the stomach stays displaced upward rather than returning to its normal position.
Types of Hiatus Hernia
There are two main types, and they behave very differently:
Sliding hiatus hernia (Type I) is by far the most common, accounting for roughly 95% of cases. The junction where the esophagus meets the stomach slides upward through the hiatus. It often moves up and down depending on your position and what you’re doing, which is why it can be intermittent. This type is the one most associated with acid reflux.
Paraesophageal hernia (Types II, III, and IV) is less common but more concerning. In this type, the junction between the esophagus and stomach stays in its normal position, but a portion of the stomach (or in severe cases, other organs) squeezes up alongside the esophagus through the hiatus. Because the herniated portion can become trapped or twisted, paraesophageal hernias carry a higher risk of complications.
What Causes It
The exact cause varies from person to person, but it comes down to anything that weakens the hiatus or increases pressure inside the abdomen. Age is the biggest factor. The muscles and connective tissue around the hiatus naturally weaken over time, which is why hiatus hernias become dramatically more common as people get older. Research from the Cleveland Clinic estimates that 50% of people over 50 have one, rising to 70% of those over 70.
Obesity is a major risk factor. Excess abdominal fat increases the pressure pushing upward against the diaphragm, and research suggests that obesity actually changes the composition of the connective tissue itself, making it more prone to stretching and hernia formation. Waist circumference specifically, not just overall body weight, is linked to both hiatus hernias and the erosive esophagitis that often accompanies them. People with morbid obesity have both a higher rate of developing hiatus hernias and a higher rate of recurrence after surgical repair.
Other contributors include pregnancy, chronic heavy coughing, repeated heavy lifting, and chronic straining during bowel movements. Some people are born with an unusually large hiatus, which makes herniation more likely later in life.
Symptoms
Most small hiatus hernias produce no symptoms at all. When they do cause problems, acid reflux is the hallmark. The hernia disrupts the normal barrier that keeps stomach acid from flowing back into the esophagus, leading to:
- Heartburn: a burning sensation in the chest, often worse after meals or when lying down
- Regurgitation: a sour or bitter taste in the back of the throat from stomach acid or food coming back up
- Difficulty swallowing: a feeling of food getting stuck, particularly with larger hernias
- Chest pain: which can sometimes feel alarming because it mimics heart-related pain
- Bloating and belching: especially after eating
Larger paraesophageal hernias can cause a feeling of fullness after eating very little, shortness of breath (because the stomach is taking up space in the chest cavity), and in some cases, anemia from slow, chronic bleeding where the stomach rubs against the diaphragm.
How It’s Diagnosed
Many hiatus hernias are discovered incidentally during tests for other conditions. When a doctor suspects one, upper gastrointestinal endoscopy is the most common diagnostic tool. During this procedure, a thin flexible camera is passed down the throat to visualize the esophagus and stomach directly. A hiatus hernia is confirmed when there’s a gap of more than 2 cm between the point where the esophagus meets the stomach and the impression of the diaphragm. The doctor measures this using markings on the scope that are spaced 5 cm apart.
A barium swallow, where you drink a chalky liquid and then have X-rays taken, can also reveal a hiatus hernia and is sometimes better at showing the size and movement of the hernia in real time. CT scans occasionally pick up hiatus hernias as well, particularly the larger paraesophageal type.
Lifestyle Changes That Help
For the majority of people with a hiatus hernia, symptoms can be managed without surgery. The goal is to reduce acid reflux by minimizing the amount of acid that escapes upward.
Meal timing and size matter more than most people expect. Eating smaller, more frequent meals rather than three large ones reduces the amount of pressure inside the stomach at any given time. Avoid lying down for at least three hours after eating, which means dinner should be well before bedtime. Gravity is your ally here.
Raising the head of your bed by about 20 cm (8 inches) helps prevent nighttime reflux. The key is to elevate the entire head end of the bed using blocks or a wedge under the mattress, not to pile up pillows. Extra pillows can actually bend your body in a way that increases abdominal pressure and makes things worse.
Certain foods and drinks tend to relax the valve between the esophagus and stomach or irritate the esophageal lining: alcohol, caffeine, chocolate, tomatoes, fatty foods, spicy foods, and acidic drinks like citrus juice. You don’t necessarily need to eliminate all of these, but paying attention to which ones trigger your symptoms is worth the effort. Losing weight, if you’re carrying extra pounds, can significantly reduce both the severity and frequency of symptoms. Smoking also weakens the valve at the base of the esophagus, so quitting helps.
Acid-reducing medications, both over-the-counter antacids and stronger prescription options that lower acid production, are commonly used alongside these lifestyle changes.
When Surgery Is Needed
Surgery is typically considered when lifestyle changes and medication fail to control symptoms, or when a paraesophageal hernia poses a risk of complications. The decision depends on the hernia’s size, type, severity of symptoms, and whether non-surgical approaches have been given a fair trial.
The most common surgical procedure involves wrapping the top of the stomach around the lower esophagus to reinforce the valve and then repairing the widened hiatus. This is usually done laparoscopically through small incisions. About 90% of people who have this surgery don’t need a second operation, though recurrence rates are higher in people with obesity.
Some people with hiatus hernias that cause no symptoms may still be offered surgical repair in specific circumstances, particularly if the hernia is large and at risk of complications, but this is handled on a case-by-case basis.
Complications to Be Aware Of
The vast majority of hiatus hernias are harmless. The serious risk, though rare, applies mainly to paraesophageal hernias where a portion of the stomach can become trapped (incarcerated) in the chest. If the blood supply to that trapped portion gets cut off, the tissue can start to die within as little as four hours. This is called strangulation, and it’s a medical emergency.
Warning signs include sudden severe abdominal or chest pain that doesn’t let up, nausea and vomiting, and skin color changes around any visible bulge. This situation requires emergency treatment. Left untreated, the dead tissue can lead to gangrene and life-threatening infection. These complications are uncommon, especially with the sliding type that most people have, but they’re worth knowing about if you’ve been diagnosed with a paraesophageal hernia.