Yawning Cools the Brain

August 30, 2019
Why do we yawn? Does it have anything to do with our health? Neuroscientist Raquel Marin gives an overview of the importance and function of yawning.

Under normal conditions, scientists estimate that people yawn approximately 28 times a day. You spend approximately four minutes every day on this seemingly unnecessary and often uncontrollable activity. You’ll spend your whole life yawning, starting during the fifth month of gestation and ending in your last few days of life. In certain contexts, it’s rude to yawn. Yawning, however, is necessary for your health. That’s because yawning cools the brain, among other things.

Keep reading to lean more.

Why do you yawn?

You probably associate yawning with being tired or bored, but that’s only part of the story. Fetuses also yawn, as do most vertebrates (fish, reptiles, birds, and mammals).

In many cultures, people consider it rude to yawn in public. Nevertheless, everyone does it, even very well educated people. Not only that, but yawning can be very contagious. All you have to do is see someone yawn in your immediate vicinity to feel compelled to do the same.

Yawning is necessary for the health of your brain. It contributes to proper brain development and functioning throughout your life.

A guy yawning outside.

Fetal yawning helps with brain development

As we mentioned above, even unborn babies yawn. They start around week 20 and continue doing so for the rest of their lives.

Babies in the womb don’t yawn because they are bored or tired, obviously. In this stage of their growth, yawning fosters sequential and ordered brain development. Many studies indicate that yawning is a sign that the brain and the peripheral nerves that regulate muscle movement are developing properly.

Fetal yawning is so important that its absence can be a sign of neural dysfunction. 

After you’re born, your brain needs you to yawn several times a day.

Yawning helps you pay attention

Most people think that humans yawn to help get more oxygen to the brain. This theory, however, doesn’t hold any water. After all, you breathe continuously day and night through your mouth and nose and it doesn’t have anything to do with brain oxygenation.

The oxygen that supplies your brain cells is primarily transported by your network of blood vessels that converge in the brain. If the purpose of yawning was brain oxygenation, then why don’t you yawn more when you’re holding your breath? Or when you’re in oxygen-deprived environments?

Thus, that explanation doesn’t hold up to scrutiny. There are other, more recent explanations that suggest that yawning allows you to go switch from a default-mode network to an attentional network. According to Walusinski (2014), yawning increases the amount of fluid in the brain, which allows increased attention and concentration that you need for more complex tasks. In other words, yawning somehow helps you switch tasks and fully concentrate.

Other studies suggest that yawning cools the brain by helping to regulate temperature.

Yawning cools the brain

Try this experiment developed by researchers from the University of Albany. To begin, you have to be surrounded by people and ready to yawn.

Place a cold pack on your forehead. Be careful not to damage your skin if it’s too cold. The reason why you have to place it on your forehead is that your forehead has more sweat glands to cool you off than any other part of your body.

With the cold pack on your forehead, your urge to yawn when the people around you yawn could be five times less than normal. If you place a hot pack on your forehead, however, your urge to yawn won’t diminish.

This experiment shows that cooling your forehead would help to cool the brain and eliminate the contagious yawn. You could also try breathing intensely through your nose to increase cooling. That might work as well.

The increased ventilation that happens when you yawn helps reduce the temperature of your brain. Lack of sleep and mental exhaustion after strenuous mental activity increases brain temperature. That’s why you yawn more when you get up or go to bed, or if you’ve been working for a while on something mentally taxing. Although most people still consider yawning to be rude in certain contexts, it’s a normal and necessary activity.

Yawning cools the brain of a woman working on her computer.

Yawning more than normal can be a sign of brain pathologies

We’ve talked about how yawning is a good thing in general. Too much yawning, however, can be a sign of illness. What’s too much? Continuously yawning more than three times every fifteen minutes.

Patients who suffer from strokes, multiple sclerosis, Parkinson’s, migraines, brain tumors, intracranial hypertension, chronic insomnia, or epilepsy tend to yawn much more than normal. In the case of Parkinson’s, continuous and excessive yawning is one of the symptoms of the disease.

If you yawn more than normal one day, there’s no need to worry. Maybe your brain is fatigued and needs to cool down. Remember that yawning is very normal.

Another possible cause of excessive yawning is consuming certain pharmaceutical drugs such as antidepressants, opioids, or tranquilizers. Drinking too much caffeine can also make you yawn more often.

If reading this article made you yawn, that’s great! That means that it sparked your interest and boosted your brain activity. Yawn away!