Category: Gross But True

Most burps are not mysterious gas being manufactured by the stomach.

They are mostly air that entered the digestive system from the outside.

You swallow small amounts of air throughout the day.

Eventually some of it comes back.

We swallow air while eating and drinking

Every time you eat or drink, a little air can go down with the food or liquid.

Eating quickly, drinking through a straw, chewing gum, talking while eating, or gulping can increase the amount.

That swallowed air can collect in the upper stomach.

Carbonated drinks add extra gas

Soda and other fizzy drinks contain dissolved carbon dioxide.

When the drink warms and pressure changes inside the stomach, some of that gas comes out of solution.

Now there is more gas available to move upward.

That is why a carbonated drink can produce a rapid series of burps.

How does the gas get back out?

A muscular ring between the esophagus and stomach normally helps keep stomach contents from moving upward.

When gas pressure builds, that area can relax briefly.

Gas travels into the esophagus and then out through the mouth.

That is a belch or burp.

Why do some people burp more than others?

Eating habits matter.

So do carbonated drinks, gum chewing, anxiety, and the amount of air a person unconsciously swallows.

Digestive conditions can affect burping too.

Occasional burping is completely normal.

Is a burp the same as a fart going the wrong direction?

No.

A burp mostly involves swallowed air or gas in the upper digestive tract.

Intestinal gas is produced farther down, often by bacteria fermenting food in the large intestine.

The two exits are handling somewhat different inventories.

Why can burps smell?

If gas carries odors from recently eaten food or stomach contents, a burp can have a noticeable smell.

But many ordinary burps are mostly odorless air.

So a burp is not usually your stomach creating some strange internal weather event.

It is mostly returning air you accidentally mailed there earlier.

A related explanation is Why do we fart?, which looks at another familiar effect from the same general system.

And that’s the short explanation.

Related explanations: Why do we fart?, Why does soda fizz?, and Why do we get hiccups?

Children sometimes pick their noses and eat what they find.

Science does not have one proven universal explanation for why.

Curiosity is probably part of it

Young children investigate the world through touch and taste.

They also have fewer social rules firmly installed.

Something that adults immediately label disgusting may simply be interesting to a child.

Habit can take over

A behavior that starts from curiosity can become automatic.

Nose picking may happen during boredom, concentration, stress, or television watching.

Once the material is on a finger, eating it may become part of the same habit.

The taste and texture may matter

Mucus contains water, salts, proteins, cells, and trapped material.

Some children may simply find the salty taste or texture interesting.

That does not mean the behavior has a hidden nutritional purpose.

Is there a health benefit?

Claims that eating boogers deliberately trains the immune system go beyond the evidence.

Your immune system already encounters microbes constantly.

There is no medical need to add nose contents to the menu.

What are boogers anyway?

Boogers form when nasal mucus traps particles and then dries.

So the material is basically used air-filter material from the nose.

Not exactly a culinary recommendation.

Should parents panic?

Occasional nose picking is extremely common in children.

The bigger concerns are injury from aggressive picking, nosebleeds, or a compulsive habit that causes problems.

There is no elegant scientific answer.

Sometimes the explanation may simply be that it was there.

And that’s the short explanation.

Related explanations: Why do boogers form?, Why does your nose get stuffy?, and Why does morning breath smell?