Why do we become overtired?
ASK A RESEARCHER: If our body becomes unbalanced, it can be difficult to sleep.
Have you ever stayed awake for too long and suddenly felt completely strange?
Maybe you became extra giggly, hyper, or simply unfocused?
Then you might have been overtired.
But what does that actually mean, and why does it happen?
Harder to focus
Our body has a kind of internal clock that helps us know when to be awake and when to sleep, explains sleep researcher Giovanna Calogiouri.
She works at the University of South-Eastern Norway.
This internal clock is called the circadian rhythm, and it often determines how we react to things.
If we lose this rhythm, we feel it in many ways.
"For example, we may have trouble focusing or feel more stressed," says Calogiouri.
Hormones control sleep and wakefulness
There are many things that can affect our sleep, but two hormones are particularly important to understand. Hormones are substances that the body uses to trigger various processes.
Melatonin is the body's sleep hormone, and its levels increase in the evening.
It slows the heart rate and slightly lowers body temperature, making it easier to fall asleep.
Cortisol is a stress hormone that keeps us awake and active throughout the day. Normally, its levels drop in the evening.
When melatonin levels are high and cortisol levels are low, we become sleepy.
But sometimes the opposite happens.
We can influence sleep
If our body becomes unbalanced, it can be difficult to sleep.
"If we look at screens or are exposed to very bright light in the evening, it can prevent the body from producing enough melatonin," explains Calogiouri.
If we are too active when our body actually wants to sleep, we may produce more of the stress hormone cortisol.
"Then we might feel overstimulated," says Calogiouri.
This could explain why we sometimes become hyper or feel strange when we are actually tired.
It's okay to have fun
Sometimes, even when we are very tired, we still can't fall asleep.
Calogiouri says that this is a common problem for people who work at different times of the day.
They often work when their body is naturally ready to sleep, which disrupts their circadian rhythm.
If we struggle with sleep for an extended period, it can be harmful to our health.
However, occasionally staying up late isn’t harmful.
"We should be allowed to have fun too," concludes Calogiouri.
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Translated by Alette Bjordal Gjellesvik
Read the Norwegian version of this article on ung.forskning.no
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