Hiatal hernias are very common, affecting an estimated 15% to 20% of adults in Western countries. That number climbs sharply with age: roughly 50% of people over 50 have one, 60% of those over 60, and 70% of those over 70. Most people with a hiatal hernia never know they have one because it causes no symptoms at all.
Overall Prevalence by Population
A hiatal hernia occurs when part of the stomach pushes up through the opening in the diaphragm where the esophagus passes through. The 15% to 20% figure commonly cited for Western populations is based on people who receive some form of imaging or endoscopy. The true number may be higher, since many hiatal hernias are small and never investigated.
One study using CT colonography (a type of CT scan focused on the colon) found hiatal hernias in nearly 48% of the adults scanned, though 86% of those were small. The researchers noted that the procedure itself, which involves inflating the colon with air, can temporarily push the stomach upward and make a tiny hernia appear that wouldn’t otherwise be detected. This highlights a key point: how common hiatal hernias appear depends heavily on how you look for them and what size you count.
Why Age Is the Biggest Factor
The diaphragm’s hiatal opening naturally loosens over time. Connective tissue weakens, and the muscles around the opening lose tone. This is why prevalence tracks so closely with age. According to Cleveland Clinic data, the progression is striking:
- Over age 50: about 50%
- Over age 60: about 60%
- Over age 70: about 70%
If you’re younger than 50 and have been told you have a hiatal hernia, you’re in a smaller group, but it’s not unusual. Pregnancy, frequent heavy lifting, chronic coughing, and repeated straining can all contribute to developing one earlier in life.
Gender and Body Weight Differences
Women are roughly 1.8 times more likely to have a hiatal hernia than men. A large imaging study published in BMJ Open Gastroenterology found a prevalence of 12.7% in women compared to 7.0% in men. The reasons aren’t entirely clear, but pregnancy-related abdominal pressure and differences in connective tissue composition likely play a role.
Body weight is another significant factor. Among people with morbid obesity, hiatal hernia prevalence jumps to 20% to 53%, compared to the 15% to 20% baseline in the general Western population. The extra abdominal fat increases pressure on the stomach, pushing it upward through the diaphragm’s opening. This is also why acid reflux and hiatal hernias so often travel together in people carrying significant extra weight: reflux rates in the same morbidly obese population range from 39% to 61%.
Most Hiatal Hernias Cause No Symptoms
The majority of people with a hiatal hernia are completely asymptomatic. A small hernia, where just a bit of the upper stomach slides above the diaphragm, typically doesn’t interfere with digestion or cause discomfort. Many are discovered incidentally when a person gets an upper endoscopy, CT scan, or barium swallow for an entirely unrelated reason.
When symptoms do occur, they usually relate to acid reflux: heartburn, regurgitation, difficulty swallowing, or a sensation of food getting stuck. Larger hernias (generally those extending more than 2 centimeters above the diaphragm) are more strongly associated with these problems. The hernia itself isn’t painful in most cases. What causes trouble is the disruption of the natural valve mechanism between the esophagus and stomach, which allows acid to flow backward.
Small Versus Large Hernias
Size matters more than the mere presence of a hiatal hernia. The vast majority are small sliding hernias, where the junction between the esophagus and stomach shifts slightly above the diaphragm. These come and go with changes in abdominal pressure, which is partly why prevalence numbers vary so much between studies. A hernia visible during one test might not show up on another.
Large hiatal hernias, sometimes called paraesophageal hernias, are far less common and more clinically significant. In one CT study, only about 1% of detected hiatal hernias were classified as large. These involve a larger portion of the stomach (or occasionally other organs) sliding through the diaphragm, and they’re more likely to cause symptoms or complications like ulceration, bleeding, or in rare cases, the stomach becoming trapped above the diaphragm.
What the Numbers Mean for You
If you’ve been told you have a hiatal hernia, you’re in very large company. For most people, it’s a normal anatomical variation that becomes more common with every decade of life. The presence of a small hiatal hernia on an imaging report doesn’t mean something is wrong or that treatment is needed.
The people who benefit from treatment are those with persistent reflux symptoms that don’t respond to lifestyle changes, or the small percentage with large hernias causing mechanical problems. If your hernia was found incidentally and you have no symptoms, it generally requires no follow-up or intervention. The high prevalence numbers reflect a condition that, in most cases, is simply part of how the body changes over time.