What is a hiatal hernia?

Ask the doctors

Q. My partner just got diagnosed with a hiatal hernia. What is it, and is it dangerous?

A. Hiatal hernias are very common. They occur when part of the stomach pokes through a natural gap (called a hiatus) in the diaphragm, which is a muscle separating your chest from your abdomen. Normally the esophagus connects with the stomach through this hole, but in some cases, the upper part of the stomach slides upward through the hiatus. The most common cause is weakened musculature that surrounds the hiatus, which can be aggravated by straining during bowel movements, intense coughing, pregnancy, or heavy exertion.

While many people who have a hiatal hernia have no symptoms, acid reflux is common. The hernia can change the position and function of the lower esophageal sphincter — a circular muscle at the base of the esophagus that normally keeps acid inside the stomach. The sphincter does not always close when it should, allowing irritating stomach acid to escape into the esophagus, which can cause heartburn.

The good news is that most people with a hiatal hernia don't need treatment, and fewer than 5% of people with a hiatal hernia need surgery to fix the problem. If you are experiencing acid reflux symptoms, such as heartburn, it may be helpful to eat smaller meals and avoid eating within two hours of bedtime at night. If your doctor thinks it's necessary, you may also want to take an antacid.

Illustration by Michael Linkinholker