It is all such a yawn

Most of us will yawn at some time or another – opening our mouths to stretching point, dropping our jaw and inhaling air. It is an involuntary action (something that just happens, we don’t think “let’s have a yawn now”) and all ages, from new born babies to the elderly, yawn from time to time.

Humans have been yawning since we evolved although the word yawn is fairly recent – it dates from Yenen or Yonen in Middle English which came from Ginian or Gionian in Old English meaning to open the mouth wide or to gape.

This opening of the mouth in a yawn enables us to inhale a large quantity of air, expanding the lungs to capacity. It also stretches the eardrums. If you yawn and physically have a stretch at the same time, there is a medical word for it – pandiculation (could be good for a pub quiz!).

But for all that, scientists are still not clear or even united in their opinions on why we do it. Most of us associate yawning with being tired or bored, and there are also various ideas and myths about yawning.

There are several mainstream theories at the moment to explain why we yawn. One is based on physiological changes in our body. Some have thought that we yawn when we need more oxygen in the body and to get rid of an excess of carbon dioxide. However, this theory has been criticised by some scientists who have run experiments showing people who were given additional oxygen still yawned with the same frequency.

The theory that we yawn when we are bored or tired is well accepted, but is still not supported either by a majority of scientists or by medical experimentation. One researcher proved that Olympic athletes can yawn right up to the start of their race when they definitely wouldn’t be bored and most unlikely to be tired either.

More recently there has been a tendency to look to the theory of brain cooling as the real reason for yawning. When the brain becomes a little overheated, the yawning brings in an excess of outside cooling air.

Some scientists have been working on the association between yawning and stretching. Often yawns are accompanied by an urge to stretch one’s muscles, something that makes them function more effectively. Yawning could therefore be a way to help ensure the lungs and throat muscles are prepared for a surge in physical activity, or to keep them active when the body is showing signs of slowing down. People facing dangerous situations have been known to yawn although they are certainly not sleepy.

An offshoot of this theory is that in early man yawning was a way of showing our teeth to intimidate others in a dangerous situation and this has remained with us in a more subtle form today. Other theories include an idea that yawning is a way to communicate with others in one’s “tribe” to indicate alertness.

As we understand more and more about the chemical make-up of our bodies and brains some more complex theories are being suggested to explain the yawn. One group of researchers have found that yawns are caused by the same chemicals or neurotransmitters in the brain that also affect our emotions, our mood and our appetite. These chemicals include serotonin, dopamine, glutamic acid and nitric oxide. It seems a change in the level of these compounds in the brain affect the frequency of yawning. It has also been shown that more opioid neurotransmitters in the brain (such as endorphins) reduce the likelihood of yawning.

Without doubt yawning is far more complex than most of us realised. The contagious aspect – being triggered into yawning when we see someone else yawn – is also a whole area of undergoing research with no current clear results other than contagious yawning indicates empathy with others.

The good news of course is that yawning is in no way dangerous. The only concern is when you find you are yawning far more than usual. This can be caused by a vasovagal reaction, when the vagus nerve which runs down from the brain and throat to the abdomen, interacts with some blood vessels. This can indicate anything from sleep disorder to bleeding in the aorta or even a heart attack, and so if you are suddenly yawning a lot for no real reason you can think of, it is best to seek medical advice.

Otherwise, you can simply treat yawning as...well, just a bit of a yawn!

Keep in touch with everything happening in Laterlife Today!

Subscribe to our free monthly email newsletters for the latest articles, offers and events. You can unsubscribe at any time should you want to.