Most animals, including humans (that’s us!) need sleep – but why?

Our brains and bodies are super busy during the daytime. It’s hard work keeping up with everything we do in a day - going to work or school, hanging out with friends, learning new things and exercising. Our brains and bodies are built to do this, but they can’t keep running for days on end! When we sleep, we give our brains and bodies time to rest and recover.

🔋 Sleeping recharges our batteries - it helps us feel more alert, energised and ready to take on the day! 🔋

What happens when we sleep?

During the daytime, our bodies and brains are busy keeping up with all the fun things we are doing. The brain is picking up lots of information in every second that we are awake - sights, sounds, smells, new feelings and experiences. All this information can’t just sit around untouched!

When we are asleep, our brains can switch into admin mode. All the new information we picked up gets sorted out and organised. The less important information might go into short-term storage until it’s used again or no longer needed. The really important stuff gets put away into the brain’s long-term storage so it’s easy to find when we next need it.

💡 A good night’s sleep helps us to think clearly and remember things we have learned! 💡

But I’m not sleepy… What happens when we don’t sleep?

When we don’t sleep, our brain doesn’t get as much time to do all of the organising it needs. That means it can be harder to remember things or do hard tasks. A tired brain might make us feel more grumpy or moody, and we might notice that little things that don’t normally bother us are making us feel stressed. A tired brain also makes it hard to deal with difficult feelings!

This is because a tired brain isn’t as good at communicating. Parts of the brain that usually talk to each other might talk less when we don’t get enough sleep - or they might talk more. The parts of your brain that react to danger, such as the amygdala, can be extra sensitive if we miss out on sleep. Other parts of the brain that talk to the amygdala also work differently if we don’t get enough sleep, making it harder to calm down when we’re stressed.

Just like in the brain, a tired body doesn’t work as well. Without enough time to heal our bodies, our immune system might start to struggle. This might make us get sick more easily. Being tired might also make you not want to exercise - something we’ve already learned is important for well-being!

How do we sleep well?

There’s two main pieces to a good night’s sleep - sleep quantity and sleep quality.

Sleep quantity just means the amount of sleep we get. The perfect amount of sleep is different for everyone, and depends on how old you are. According to the experts:

👶 Babies need around 12-16 hours, including naps.
🌱 Toddlers need around 11-14 hours of sleep, with naps.
🌼 Kids between 3 and 5 years old need around 10-13 hours of total sleep.
🍄 School-aged children (6-12 years old) need around 9-12 hours.
🌵 Teenagers (13-18 years old) need around 8-10 hours.
🌳 Adults (18+ years) need 7 or more hours.

Sleep quality is all about getting a refreshing and uninterrupted night’s sleep. That means falling asleep at a good time and not getting woken up during the night. Having a bedtime routine - doing the same calming things every night before bed - can help you get a good night’s sleep. Being consistent - keeping it up even on weekends - helps our brain learn to start sending out sleepy signals when you start your routine!

Caffeine and sugary drinks before bed can make it harder to get good sleep. These can mess with our body clock - our circadian rhythm - and stop our brains sending out sleepy signals at the right time. Too much light, especially blue light from phone and tablet screens can do the same thing! That’s why it’s best to put the screens away at least an hour before bedtime and switch to relaxing activities.

Want to learn more?

Here’s some more links you can check out to keep learning about the science behind sleep and well-being: