Why Do We Burp?

Most of the air in a burp got into your body because you swallowed it. Small amounts of air slip down when you eat, drink, talk, or simply swallow. You don’t notice it happening. But when enough air collects in your stomach or lower esophagus, it needs somewhere to go. A burp is that air coming back up and out through your mouth.

Where Does the Air Come From?

You don’t have to deliberately gulp air to swallow some of it. Every time you swallow food or a drink, a little air can go along for the ride.

Fizzy drinks make the connection easier to notice. Soda, sparkling water, and other carbonated drinks contain dissolved carbon dioxide. Once some of that gas is released inside your stomach, there’s more gas available to come back up. That’s why a few big burps after a fizzy drink aren’t exactly a mystery once you know where the gas came from.

Why Does the Air Come Back Up?

As air collects, it puts pressure on the upper part of your digestive tract. At some point, the muscles between your stomach and esophagus relax enough to give that air a way out. The gas moves upward through your esophagus and escapes through your mouth.

That’s also why you don’t necessarily burp the instant you swallow some air. It can hang around for a bit before enough collects to make its way back up.

Is It the Same Gas as Passing Gas?

Not usually. A typical burp is mostly getting rid of air or gas from the upper digestive tract. Much of the gas that eventually leaves the other way forms farther along in the intestines as food is broken down.

So even though both involve your body getting rid of gas, they’re not simply the same gas choosing between two exits. A burp is dealing with air and gas that’s still near the beginning of the digestive tract.

This article is for informational purposes only and is not a substitute for professional medical advice.