Is a Hiatal Hernia the Same as a Diaphragmatic Hernia?

A hiatal hernia is not the same thing as a diaphragmatic hernia, but it is one specific type. “Diaphragmatic hernia” is the umbrella term for any condition where organs push through an opening or defect in the diaphragm, and hiatal hernias happen to be the most common variety. The distinction matters because the other types of diaphragmatic hernia, particularly congenital ones found in newborns, carry vastly different risks and require very different treatment.

The Diaphragm Has More Than One Weak Spot

Your diaphragm is a dome-shaped muscle that separates your chest cavity from your abdomen. It already has natural openings where the esophagus and major blood vessels pass through, and it can also develop defects from incomplete formation during fetal development or from physical trauma. A diaphragmatic hernia occurs when abdominal organs slip through any of these openings or defects into the chest. Hiatal hernias, Bochdalek hernias, Morgagni hernias, and traumatic diaphragmatic hernias are all members of this family, but they differ in where the defect is, when it develops, how dangerous it is, and who it affects.

How Hiatal Hernias Work

A hiatal hernia happens at the hiatus, the natural opening in the diaphragm where the esophagus passes through on its way to the stomach. In a healthy setup, the diaphragm wraps snugly around the lower esophagus and works with the lower esophageal sphincter to keep stomach acid from flowing upward. When part of the stomach pushes up through the hiatus into the chest, that partnership breaks down. The sphincter gets displaced upward and separated from the diaphragm’s squeezing action, which lowers the pressure keeping acid where it belongs and makes reflux more likely.¹

Hiatal hernias are overwhelmingly acquired rather than congenital. They develop over time from age-related weakening of the tissues around the hiatus, obesity, chronic coughing, heavy lifting, or some combination of these. Research on the phrenoesophageal ligament, the membrane that anchors the esophagus at the hiatus, has found that people with hiatal hernias have less total collagen in this ligament compared to people without the condition, suggesting that tissue quality plays a role in why the opening gradually loosens.²

These hernias are remarkably common. A retrospective study of patients undergoing endoscopy found that roughly 30% had a hiatal hernia, with similar rates across men and women and across age groups above and below 60.³ Many of those people had no idea they had one, which is typical. Most hiatal hernias are small, cause no symptoms, and are found incidentally during imaging or endoscopy done for unrelated reasons.

Congenital Diaphragmatic Hernias Are a Different Problem Entirely

Congenital diaphragmatic hernia (CDH) is present at birth and results from the diaphragm not forming completely during fetal development. Unlike hiatal hernias, which involve the stomach sliding through an existing opening, CDH involves a hole in the diaphragm that was never supposed to be there. Abdominal organs, often the intestines, stomach, and even the liver or spleen, push up into the chest cavity and crowd the developing lungs, leading to underdeveloped lungs (pulmonary hypoplasia) that can be life-threatening.⁴

The two main types of CDH are named after the surgeons who first described them. Bochdalek hernias occur through a defect in the back and side of the diaphragm, usually on the left, and account for the vast majority of congenital cases. Morgagni hernias are much rarer and occur through a defect at the front of the diaphragm, near the sternum.⁵ Having both simultaneously is extremely unusual.⁶

The history of treating CDH stretches back centuries. The condition was first described in 1575, though it took until 1848 for Bochdalek to characterize the posterolateral defect that now bears his name. Successful surgical repair in an infant was first performed in 1902, and the first surgery on a newborn within 24 hours of life was not reported until 1946.⁷ Even today, CDH remains a serious birth defect with significant mortality. A large multicenter Japanese study of 747 patients found a survival rate of about 84%, with the remaining 16% not surviving. Among survivors, complications were common in the early years, affecting over 45% of children at age one and a half, and roughly a third still had complications at age six.⁸

This is the starkest difference between a hiatal hernia and other diaphragmatic hernias. A hiatal hernia might give you heartburn. A Bochdalek hernia in a newborn can be fatal.

Traumatic Diaphragmatic Hernias

A third category sits outside both the hiatal and congenital camps. Blunt force trauma from car accidents, falls, or penetrating injuries like stab wounds can tear the diaphragm, creating a hole through which abdominal organs herniate into the chest. These traumatic diaphragmatic hernias can be acute emergencies or, if the initial tear is missed, they can present months or even years later as chronic hernias when the defect gradually enlarges and organs migrate upward.

Surgery is the standard treatment for traumatic diaphragmatic hernias. When the diaphragmatic wound is small enough, surgeons close it directly with sutures. Larger defects that cannot be pulled together without tension may require a prosthetic patch, typically made of PTFE. In contaminated or infected surgical fields, a biological prosthesis is preferred over synthetic material.⁹

Why the Diagnostic Confusion Happens

Despite the very different origins and risks, these conditions can look similar on initial imaging and share overlapping symptoms. Chest pain, shortness of breath, nausea, and difficulty swallowing can all appear with hiatal hernias, Bochdalek hernias, and traumatic hernias alike.¹⁰ In newborns, a large hiatal hernia that pushes the stomach well into the chest can mimic a congenital diaphragmatic hernia on X-ray, creating a genuine diagnostic puzzle that requires additional imaging to sort out.¹¹

Getting the distinction right matters for treatment planning. For hiatal hernias, multiple imaging tools are available. Barium swallow radiography remains a go-to method: swallowing contrast material while being X-rayed lets the doctor see exactly where the stomach sits relative to the diaphragm. Endoscopy allows direct visual inspection of the esophageal lining and can pick up complications like Barrett’s esophagus and ulcers, though it sometimes exaggerates hernia size due to air inflation during the procedure. CT scans, while not routinely recommended for hiatal hernias alone, help distinguish a hernia from other chest conditions and can provide detail on size and position. Esophageal manometry can confirm a hiatal hernia by measuring the gap between the lower esophageal sphincter and the diaphragm.¹²

For congenital and traumatic diaphragmatic hernias, CT and occasionally MRI tend to be more central to the diagnostic workup because these conditions often need detailed cross-sectional imaging to identify the exact location of the defect, what organs have herniated, and whether there are complications like bowel strangulation.¹³

Treatment Looks Very Different Across Types

For hiatal hernias, most people never need surgery. Small, asymptomatic hernias found by accident are typically left alone. Data suggests that asymptomatic hiatal and paraesophageal hernias become symptomatic at a rate of only about 1% per year, making watchful waiting a reasonable approach.¹⁴ When symptoms do develop, they are usually reflux-related, and the first line of treatment is acid-suppressing medication. Patients with hiatal hernias who have reflux-associated symptoms may respond to medication, though the presence of a hernia does tend to blunt the effectiveness of treatment compared to reflux patients without a hernia.¹⁵

When hiatal hernia surgery is needed, it typically involves pulling the stomach back below the diaphragm, closing the widened hiatus with sutures, and often wrapping the top of the stomach around the lower esophagus (a fundoplication) to reinforce the anti-reflux barrier. Nissen fundoplication is the most commonly performed version of this procedure.¹⁶ For larger hiatal hernias, surgeons may reinforce the repair with mesh around the esophageal opening to reduce the chance of recurrence.¹⁷

Congenital diaphragmatic hernias, by contrast, almost always require surgery, and often urgently. The goal is to return the herniated organs to the abdomen and close the diaphragmatic defect. When the hole is small enough, direct suture repair works. For larger defects where pulling the tissue together would create too much tension, a prosthetic patch is used.¹⁸ Patch repair is effective but carries a higher recurrence risk: in the Japanese multicenter study, about 11% of survivors had a recurrence by age three, and roughly 70% of those recurrences were in children who had undergone patch repair.⁸

When a Hiatal Hernia Gets Dangerous

While hiatal hernias are usually benign, large ones can occasionally lead to a serious complication called gastric volvulus, where the stomach twists on itself inside the chest. This cuts off blood supply and can cause tissue death if not treated quickly. The condition is rare, but case reports describe patients presenting with persistent vomiting and chest pain, with imaging revealing the twisted stomach behind the heart. Emergency surgery to untwist the stomach, close the hiatal defect, and perform a fundoplication is the typical intervention.¹⁹

Large hiatal hernias can also cause Cameron ulcers (sores on the stomach lining where it rubs against the diaphragm), chronic bleeding leading to anemia, and in rare instances, breathing difficulty from the stomach compressing lung tissue. These complications are the main reasons doctors recommend surgical repair even in patients whose primary complaint is not reflux.

The Incidental Finding Problem

One practical issue that trips up many patients is the incidental discovery of a hiatal hernia on a CT scan done for something else entirely. A study using natural language processing to identify these cases found that about 10.6% of CT scans contained an incidental hiatal hernia, but only 1.2% of those patients received a referral for follow-up. While most of these incidental findings are small and clinically irrelevant, moderate and large hernias can be lost to follow-up and may eventually cause problems that could have been anticipated.²⁰ If you have been told you have a hiatal hernia as an incidental finding, it is worth asking your doctor whether the size warrants periodic monitoring even if you feel fine.

Morgagni Hernias in Adults

Most discussions of congenital diaphragmatic hernia focus on newborns, but Morgagni hernias occasionally go undetected until adulthood. Because the defect is at the front of the diaphragm and tends to be smaller than a Bochdalek defect, a Morgagni hernia may cause only vague symptoms for decades before being diagnosed, often incidentally on chest imaging. Adults may present with chest discomfort, bowel complaints, or respiratory symptoms when the hernia contents shift.⁵ Surgical repair is still recommended because of the risk of the herniated bowel becoming trapped and losing blood supply, even in cases where symptoms are mild.

This scenario illustrates why the terminology matters. Telling an adult patient they have a “diaphragmatic hernia” without specifying the type can cause unnecessary alarm if they associate the term with the life-threatening neonatal condition. Conversely, dismissing a Morgagni hernia as “just a diaphragmatic thing” can lead to under-treatment of something that genuinely needs repair. The type of diaphragmatic hernia drives every subsequent decision, from how urgently it needs treatment to what the surgery looks like to what the long-term outlook is.