Yawning is a common phenomenon that affects us all, but do you really know what it means and why it happens? Discover 6 things you need to know about yawning to better understand this natural bodily reaction.
1. Yawning is a reflex
Yawning is an involuntary reflex that manifests itself in the opening of the mouth accompanied by a deep inhalation followed by a more or less noisy exhalation. Although the exact causes of yawning are not yet known, it is thought to stimulate wakefulness and alertness by increasing blood flow to the brain and promoting oxygenation of nerve cells.
The different phases of yawning
Yawning is generally divided into three phases:
- Inspiration: the mouth opens and the diaphragm contracts, allowing a large quantity of air to enter the lungs.
- Apnea: for a few moments, breathing is blocked to allow carbon dioxide in the blood to pass into the inspired air.
- Exhalation: the carbon dioxide-rich air is expelled from the lungs, and the mouth closes.
2. Yawning is not always linked to fatigue or boredom
Contrary to popular belief, yawning is not only a sign of fatigue or boredom. It can also be caused by other factors, such as :
- Hunger: when our stomach is empty, it releases hormones that can trigger the yawning reflex.
- Stress: when faced with a stressful situation, the body produces adrenaline, which can trigger a yawn.
- Empathy: seeing or hearing someone yawn can prompt us to do the same, as if to express our understanding and support for that person.
3. Animals yawn too
Humans aren’t the only ones to yawn: many animals, especially mammals, exhibit the same reflex. In some species, yawning may have a social function, as in primates, where it establishes a hierarchy within the group by showing submission or dominance.
A possible evolutionary function
It has been suggested that yawning may have an evolutionary function in animals, enabling the body to anticipate and prepare for a change of state or situation (e.g. from rest to wakefulness).
4. Yawning is contagious
It’s well known that yawning is contagious: seeing or hearing someone yawn is often enough to trigger our own reflex. This “contagion” is partly due to the phenomenon of empathy, which leads us to share the emotions and sensations of others.
Yawning contagion varies from person to person
Some people are more sensitive to the contagion of yawning than others. This difference could be explained by genetic factors, but also by upbringing and life experiences.
5. Yawning can have beneficial effects on health
Although often perceived as a sign of fatigue or boredom, yawning can have a number of health benefits, such as :
- Stimulating wakefulness and alertness, by increasing blood flow to the brain and promoting oxygenation of nerve cells.
- Regulate brain temperature, by evacuating hot air and drawing cool air into the lungs.
- Facilitate digestion, by promoting peristalsis (the contractions of the intestine) and helping to evacuate gas from the stomach.
6. Some yawning-related disorders
In some people, the yawning reflex can be dysfunctional, leading to problems such as :
- Excessive yawning: when yawning is frequent and uncontrollable, it may be a sign of a nervous system disorder, chronic fatigue or hormonal imbalance.
- Yawning pain: yawning can sometimes cause pain in the jaw, neck or throat. This may be due to inflammation, infection or muscular problems.
In the event of unusual or painful yawning, it’s important to consult a healthcare professional to identify the cause and receive appropriate treatment.
