Why do we yawn?

Yawning is considered a sign of tiredness and sleep deprivation. There are numerous theories about the cause and significance of this natural breathing reflex, but what is the real reason we yawn, and why is it so contagious? Learn here what's behind the yawn myth and how yawning is really connected to our sleep.

Table of contents

1. The phenomenon of yawning
2. What happens when you yawn
3. Why do we yawn?
4. Why is yawning contagious?
5. What can I do about frequent yawning?
6. Conclusion

1. The phenomenon of yawning

Yawning is the involuntary and natural reflex of opening the mouth and taking a deep breath. A human yawn lasts up to six seconds, and like most vertebrates, we yawn every day, about 250,000 times in our lifetime. Yawning occurs more frequently in the morning and evening hours and is therefore often associated with a lack of sleep or poor sleep quality. While we do yawn more often when we're tired, we also yawn when we're intensely focused, hungry, or stressed.

2. What happens when you yawn?

Yawning is a natural reflex that we can only suppress or prevent to a limited extent—and probably for good reason. When we yawn, the muscles in our mouth and face tense, and the rest of our body muscles, especially our chest and neck muscles, also tighten. The diaphragm rises and falls, and our heart rate and blood flow briefly increase. Deep breathing and the brief expansion of the airways provide the lungs with more air for a short time, thus making more oxygen available.

3. Why do we yawn?

What exactly triggers the "yawn reflex" and what purpose this behavior actually serves has not yet been scientifically proven. Although this belief is widespread, frequent yawning does not appear to be a direct sign of poor or insufficient sleep. There are several different theories about the triggers and beneficial effects of yawning.

Theory: Yawning is a reaction to oxygen deficiency and tiredness!

For a long time, it was assumed that yawning occurred as a response to a lack of oxygen and served to increase oxygen supply and reduce carbon dioxide levels in the blood. Because acute oxygen deficiency is often associated with severe fatigue, yawning was understood as a natural reaction to sleepiness, with our body trying to increase oxygen supply and stay awake. But is that true? Unfortunately not! Studies now show that oxygen supply has no influence on the frequency of yawning and is not an explicit trigger.

Theory: Yawning makes you awake and alert!

Many researchers assume that yawning actually serves to keep us awake or increase our attention. Admittedly, we yawn particularly often in boring situations and during rather monotonous activities, and the stretching and expansion that accompanies breathing activates the circulatory system. However, a study from Switzerland shows that the intensity of brain activity before and after yawning is almost identical.

Theory: Yawning cools the brain and thus increases concentration!

Recent studies suggest that extensive yawning cools our brain and thus helps regulate our brain temperature. The brain also works constantly and generates heat. After sleep and when tired, brain temperature is generally elevated – It is precisely in these situations that we yawn most often.The short-term increase in heart rate during yawning allows more cool blood to reach the brain regions, lowering brain temperature. The result: The brain is protected from overheating, an optimal working temperature is maintained, and concentration and mental performance are increased. These assumptions are supported by further studies and experiments and correspond to the current state of research.

4. Why is yawning contagious?

When one person yawns, everyone yawns. We all know the contagious effect of yawning. Neuroscience attributes this to the activation of so-called mirror neurons. These are special structures in our brain that are also associated with sensitivity and empathy, causing us to "mirror" and imitate the behavior of others.

Did you know that for many people it is enough to read about yawning or to think about it in order to yawn too?

5. What can I do about frequent yawning?

Based on the theory that yawning serves to thermoregulate our brain, it can help to breathe through the nose rather than the mouth - here the incoming air is already cleaned and "tempered".

Yawning itself is a harmless and non-threatening reflex. However, suppressing it is medically unhealthy and should therefore not become a habit. So don't take it to heart if your counterpart yawns frequently during your conversation.

6. Conclusion

• Yawning is the involuntary and natural reflex of opening the mouth wide and taking a deep breath.

• When you yawn, your muscles tense, your heart rate and blood flow increase, and your lungs and brain are temporarily better supplied with air.

• The cause of yawning is not entirely known. Oxygen deprivation or fatigue are no longer considered triggers, but brain thermoregulation may be involved.

• Yawning is contagious but harmless and should not be suppressed.

Best wishes and see you soon!