Why We Yawn

Have you caught the yawn yet?
Have you caught the yawn yet? | Source

By Joan Whetzel

The two questions everyone asks, but no one has an absolute answer for, are (1) Why do we yawn? and (2) Why are yawns so contagious? All we have to do is see someone else yawn and we feel the urge to do the same. I found myself heading into fits of yawning just researching this article. I read the word yawn enough times, and I’m fighting them off like bees on at a honeycomb.

What Is Yawning?

Yawning is considered reflexive, an act that involves simultaneously inhaling deeply and stretching the eardrums by opening jaw widely. This is followed by exhaling the breath. Yawning is usually involuntary.

Causes of Yawning

The most common causes of yawning are fatigue and drowsiness. But there are other likely causes or triggers as well, such as:

· Illnesses that produce daytime sleepiness

· Vasogal reactions associated with heart diseases.

· Lack of sleep.

· Epilepsy.

· Brain tumors.

· Sleep apnea.

· Overwork.

· Boredom.

· Seeing others yawn.

· Talking to someone on the phone who yawns during the conversation.

Some theories which have not been substantiated include increased carbon dioxide levels in the bloodstream, a need for more oxygen (which is produced by the yawning), the urge to stretch, anxiety and stress, and to be caused by an increase in the same brain chemicals (serotonin, dopamine, nitric acid) that affect emotions, appetite, and mood while a decrease in yawns may occur as endorphins rise. Yawning is thought to increase the state of alertness, to control the brain’s temperature, and to reduce brain pressure.

Why Are Yawns Contagious?

One study in Finland confirmed that the contagiousness of yawning is pretty much unconscious (no surprise there) and that it bypasses the brain’s usual circuitry used when we consciously analyze and mimic the actions of other people. Many studies have been performed to try and determine the exact mechanism that produces the contagion, put the results of the testing have produced a lot of unrelated clues that are virtually indecipherable. The only things the studies agree on is that they can’t agree on, or determine, the exact reason that yawns are so contagious.


Wikipedia. Yawn.


Medline Plus. Excessive Yawning.


Right Diagnosis. Yawning.


World Science. Why Is Yawning Contagious?



Yawning Is Contagious

Why Is Yawning Contagious?

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Comments 5 comments

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Joanne M Olivieri 3 years ago

Well, this was definitely interesting. The causes, particularly a brain tumor is a little scary. Very informative

DDE profile image

DDE 3 years ago from Dubrovnik, Croatia

Amazing how much I have learned here about yawning.

ytsenoh profile image

ytsenoh 3 years ago from Louisiana, Idaho, Kauai, Nebraska, South Dakota, Missouri

I always wondered why yawning makes me nauseous. And, I always thought it was interesting how someone else's yawning causes another to yawn. Interesting hub. Thank you.

Levertis Steele profile image

Levertis Steele 3 years ago from Southern Clime

I yawned three times before I completed the reading of the first paragraph and about 15 times by the end of the hub. I had to pause for another one. Well, yawning relaxes me. Another big one!

And another interesting hub. Thanks for sharing. I am still yawning! My eyes are watery. Another one!

joanwz profile image

joanwz 3 years ago from Katy, Texas Author

LOL Thanks for sharing./

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