In VeryWell Health Magazine published last month, Dr Kristin Hayes wrote a piece titled “why do we yawn?” Which was followed with a rhetorical question “is yawning contagious?”.
As I was reflecting on the write-up, I felt the urge to yawn. Ahaa, I said to myself, that woman could be onto something. Yes, yawning is contagious. Just watch someone yawn, and you are induced to also yawn, but does that answer the question – “why do we yawn” No
Just like sneezing, research shows we sneeze when irritated, but that does not tell the whole story, since research also shows that nobody can sneeze with his eyes open. That is a topic for another day – “why do we really sneeze” the answer will shock you, just keep your fingers crossed.
What are the traditional beliefs of yawning?
ν Just think back when you were younger, whenever you yawned – what did your parents tell you “Emeka it seems you are tired?” Or “Dauda better go and sleep and stop yawning here” Or “Akeem are you feeling sleepy, why are you yawning?
• Yes our parents knew, yawning meant you were either tired or sleepy. Are there other health implications of yawning? Let us find out.
What is yawning?
a) Yawning is an involuntary deep breath, usually with your mouth open, followed by a slower exhale with your mouth closing.
b) Yawning is considered contagious – you will likely yawn, when you see someone else yawn.
c) In the 4th Century, Hippocrate first described the yawn as a method to remove “bad air”, improve oxygen flow to the brain and identity early fever. Medically Hippocrate was right.
d) Since those days we have learned more, but there is still so much we don’t understand about yawning.
What are the causes of yawning?
Yawning is believed to be related to feeling bored or sleepy, however this is over simplification.
1) Drowsiness or sleepiness
Yawning commonly occurs when sleepy. There are some thoughts that yawning is actually stimulating and a counter-measure to falling asleep.
ν Yawning, most likely occurs simply as a result of being drowsy.
2) Decreased arousal
You yawn when you are in a less stimulating environment – ie you are bored.
3) Contagious yawning
This is induced by witnessing another person yawn. Thinking about a yawn is also known to cause one to yawn.
4) Chemical causes
Androgen like testosterone, oxytocin and some medications like Prozac and other antidepressants can increase your frequency of yawning.
5) An ear protective mechanism
ν While it is true that yawning can equalise pressure, between your inner ear and the outside atmospheric pressure, by opening your Eustachian tube, it does not appear to be an evolutionary adaption to protect your ear.
ν Other methods can also equalise pressure in your ear, like chewing gum an drinking fluid.
6). Regulation of brain temperature
It has been observed that a hot and cold pack, on your forehead can change your likelihood of yawning.
ν However it is more likely, that hot pack induces yawning by decreasing your arousal state, while a cold pack increases arousal and decreases the number of yawns.
7) A response to decreased oxygen and increased carbon dioxide
While this was a common belief for a while, there is no evidence that this is indeed true.
What are the types of yaws?
1) Nose yawns – By sealing your lips during the exhalation phase of the yawn, you can actually yawn through your nose.
2) Eyes open yawn – Your eyes typically will either close or squint during yawn.
3) Clenched teeth yawn – when you feel the yawn starting, clench your teeth as you inhale. This tends to be described as our unsatisfactory yawn.
What are the benefits of yawning?
1) Equalised pressure – Yawning equalises pressure in your inner ear by opening your Eustachian tube
2) Social clues: A yawn can offer a clue about how you are feeling. You may consider this a disadvantage as well.
3) Stimulating effect – Yawns are thought to stimulate arousal and increase vigilance, when you are sleepy. This is a result of mechanical stimulation of receptors in your neck, called carotid bodies.
4) Lung proping – Yawning helps to prevent your lung from collapsing.
5) Lung protection – Yawning helps renew surfactants in the lungs, which help with breathing.
6) Tonsil cleansing – Yawning alsohelps to remove debris from your palatine tonsils.
So next time you feel like yawning, do not suppress it. Be medically guided
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