Healthy Harold on the science of sleep and why it’s so important

Hello friends, it’s me, Healthy Harold!

On April 7, 2026, we will be celebrating a special day – World Health Day! On this day we focus on one health topic for people all over the world. Wee don’t just celebrate this for one day, we explore this topic until the next World Health Day theme is chosen.

This year’s theme is, “Together for health. Stand with science.”

You might be asking, “What does this mean?” Well, the theme celebrates the power of science and how much it impacts people, animals and our planet.

Everything around us is an effect of science. Science tracks, predicts and detects up and coming risks and trends. It helps us do so many things! It can turn us into detectives as we search and experiment to find the answers to our burning questions.

There’s even science in sleeping. That’s why it’s so important that we have a good night’s rest every day, so we are ready to go to school and have fun with our friends and family. Did you know that we should be aiming to get nine to 11 hours of sleep every day? You may think that’s too much – but there is a lot that happens while we sleep.

In one night, we go through four to five sleep cycles. And in each single sleep cycle, there are four sleep stages.

Stage 1: This is when we start dozing off but our eyes do something called “slow rolling eye movements”, where our eyes move in different directions very slowly. This is something we can only do when we’re sleeping.

Stage 2: Our body and mind start slowing down. Our brain creates bursts of signals called “sleep spindle”.

Stage 3: This is also known as deep sleep. This stage is important because it helps our body grow and recover. Our brainwaves also become big and slow; which makes it harder to wake us up.

Stage 4: This last stage is called REM sleep. This stands for Rapid Eye Movement. During this time, our brain is nearly as active as when we are awake! This is when you can have those dreams that feel like real life.

But falling asleep isn’t as easy as everyone says it is. When we don’t get a good night’s sleep, we can have difficulty concentrating at school, struggle to learn new things and forget things people say to us. Sometimes, when we don’t get enough sleep, we can also be a grumpier version of ourselves and may get frustrated or angry at things normally don’t bother us.

Sleep plays an important role in keeping everyone healthy and happy. I It can help support immune function, which helps the body fight off disease and infections. It also helps us to remember memories from years ago! Is there a particular memory that makes you smile? Maybe hanging out with your friends, a family holiday or new experience? We can look back on these special moments because when we are sleeping, it gives our brain time to store precious memories that you will remember forever.

So, did you learn something new about sleep? Isn’t science amazing? I’m excited to learn how trees grow next. Let’s all celebrate World Health Day together! Next time you see a friend, share a cool, fun fact about the science that is all around us – like Kid Scientist Jayki in the video.

Rest up and stay healthy and happy!

Healthy Harold

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