Why Do You Yawn — and Is It Contagious?

Do you ever find yourself yawning when you see someone else yawn?

There are some interesting myths about this strange, wide-mouthed thing we do. Centuries ago, people believed that you should cover your mouth during a yawn to prevent your soul from leaving the body.

“We all find ourselves yawning when we feel sleepy or bored, or sometimes, for no apparent reason at all,” says family medicine physician Donald Ford, MD.

But for as much as we know about the body and how it works, laypeople and scientists alike still ponder the exact reasons why we yawn. We don’t have a definitive answer, but there are some solid theories behind why we yawn. Let’s review the main ones.

Theory 1: It’s your brain’s way of waking you up

It’s no coincidence that you frequently yawn when you feel your eyelids droop and you start daydreaming about your warm bed. In fact, a yawn might be your brain attempting to jolt you awake when you’re sleepy.

Researchers have theorized that as yawning forces your face and neck to move, this causes stimulation of your carotid artery. In turn, this causes your heart rate to increase and even to move your brain into more of an “active state.”

In other words, think of it as your body’s way of sending a gentle alarm to your head when it notices you’re dozing off.

Theory 2: It helps relieve pressure

Have your parents ever told you to try and yawn on purpose to help pop your ears when a plane lands? Well, turns out there may be some science to that tip.

“Yawns are useful in opening our eustachian tubes, which regulate air pressure in the middle ear,” says Dr. Ford.

In fact, that’s why your body often will set off a yawn as a way to relieve pressure. But the same effect also happens when we swallow — so researchers can’t say for sure if this is the main reason that we yawn.

Theory 3: It helps regulate brain temperature

Researchers have also found that yawning helps thermoregulate your brain — meaning helping your brain maintain its core internal temperature.

“They theorized that just as your computer has its own cooling mechanism to keep it from overheating, your body’s computer — the brain — uses yawning to regulate its temperature,” says Dr. Ford.

It does this in a couple of ways. Various studies have found that when we yawn, we inhale a large amount of air into our lungs, which then cools the blood vessels in our head and neck. Additionally, the facial muscles in our jaw and cheeks stretch, adjust and contract, which could help ventilate our sinuses and further cool our brain. You may have also noticed that when you yawn, it can cause you to tear up, which also releases heat.

This theory may play hand in hand with the theory that yawning is a way to make your body more awake or alert. “Sleep cycles, boredom and stress are associated with temperature fluctuations in the brain,” adds Dr. Ford.​

Is it possible to yawn excessively?

OK, now the person next to you in the meeting is giving you a side-eye because you’re on your third yawn in a row. But it’s not your fault if that’s how your body is reacting!

In addition to wondering why you yawn, you may also wonder if it’s a problem if you yawn excessively. What’s the yawning limit? It may surprise you to know that the average person yawns about 20 times a day — so, you’d have to yawn a lot more than that before you should be concerned.

And while there isn’t an exact number to what constitutes yawning too much, the main red flag you’ll want to take note of is if you’re yawning way more than is normal for you — especially if it’s not triggered by being tired or bored.

In some cases, excessive yawning can be a sign of a neurological issue, including:

• Epilepsy.
• Migraines.
• Multiple sclerosis.
• Parkinson’s disease.
• Stroke.

If you find that you’re yawning more than you normally do, it’s best to consult a healthcare provider.

Are yawns contagious?

Did you ever notice that after you see someone yawn, you feel the need to yawn yourself?

This is what we call a “contagious yawn” — and yes, it’s a thing. But there’s still a lot of mystery around the phenomenon. Someone’s initial yawn is considered a spontaneous yawn. When you yawn in response, this is considered a contagious yawn.

Research from 2011 found that both spontaneous and contagious yawns arise out of an underlying mechanism involved in regulating your brain’s temperature. So, many researchers theorize that contagious yawning is simply this: If you yawn after seeing someone else yawn, it’s likely because you’re both in the same area with a similar climate. In turn, both of your brains are responding to a temperature adjustment.

But is it possible that simply hearing or seeing someone yawn can send a trigger to your brain to yawn as well?

A recent 2022 study aimed to find out if there’s a clear link between social closeness and yawning. While the research confirmed that people did yawn if they saw others yawning, this wasn’t really because of an empathetic or emotional response. Instead, it may be a part of synchronized group behavior — as yawning helps alert or “wake up” the body, our bodies may respond to others yawning as a way to protect ourselves.

How to stop yawning

If your constant yawning is starting to annoy you (or others around you), you can do a couple of things to check in with your body.

If you want to stop yawning, you can try:

• Taking some deep breaths. Similar to getting rid of hiccups, a couple of deep breaths through your nose can help stop your never-ending yawns.
• Move around. If your yawning is due to feeling sleepy or tired (and you can’t take a quick nap), stimulating your body simply by getting up and walking could help.
• Cool down. A little bit of cold therapy may be able to calm down your yawning as well. Try walking outside and breathing in some crisp air or take some small sips of ice water.

The bottom line on yawning

Yawning is a common phenomenon that many of us experience. You may notice it happens when you’re​​​ tired or bored, but it could also be a response to stress, pressure or your brain maintaining its internal temperature.

But if you’re noticing that you’re yawning more than usual and with no clear cause, you should consider talking to a healthcare provider to see if there’s an underlying issue. And if your yawns are telling you that you’re not getting enough ZZZs, be sure to talk to your provider about any possible sleep deprivation symptoms you may be having to help you get a better night’s rest.