Sleep and Your Brain: What Happens While You Sleep?
When you’re asleep, your brain isn’t.
In fact, sleep is one of the busiest times for your brain. While your body is resting, your brain is processing information, consolidating memories, regulating emotions and carrying out some important maintenance work.
And this is one of the reasons why sleep is about so much more than just feeling rested the next day.
September is World Alzheimer’s Month, which makes it a good time to look at the relationship between sleep and brain health ~ and why protecting your sleep is one of the things you can do to support your brain over the long term.
Your brain doesn't switch off when you sleep
From the outside, sleep can look like a pretty inactive state. You're lying still, your eyes are closed and you're not consciously doing anything.
But your brain is still very much at work.
Throughout the night, you move through different stages of sleep, including non-REM and REM sleep. You cycle through these stages several times, and each one plays a different role in helping your brain and body function properly.
So while you're lying there doing absolutely nothing, your brain has plenty to do.
Your brain uses sleep to process what happened during the day
Another important thing your brain does while you sleep is some pretty important maintenance work. Your brain is incredibly active throughout the day and, like any active system, produces metabolic waste as part of its normal activity. Sleep helps the brain move and clear some of this waste through a system known as the glymphatic system.
One of the substances researchers are particularly interested in is beta-amyloid, a protein that can build up in the brain and is associated with Alzheimer's disease. There is still more to learn about exactly how the glymphatic system works and how much of a role it plays, but what we do know is that sleep is involved in some of the processes that help maintain a healthy brain.
So when we think about what your brain is doing while you sleep, it's not just resting. It's still active, processing information and carrying out some of the maintenance work it needs to function properly.
Sleep also helps your brain manage your emotions
Have you ever noticed that everything seems a little harder after a terrible night's sleep?
You're more impatient. Small things bother you. You find it harder to concentrate. You might feel more emotional than usual. That's not just because you're tired.
Sleep plays an important role in how your brain processes and regulates emotions. When your sleep is disrupted, it can be harder for your brain to manage emotional responses and make good decisions. Which helps explain why something that feels overwhelming at 10pm can sometimes feel much more manageable after a good night's sleep.
The circumstances might not have changed. Your brain has.
It's not just about how many hours you get
This is something I think is really important when we talk about sleep.
You can spend eight hours in bed and still not get the quality sleep your brain needs.
If your sleep is repeatedly interrupted, you may not move through the different stages of sleep in the way you need to. Snoring, insomnia, pain, medications, alcohol, an irregular sleep schedule and sleep apnoea can all contribute to disrupted sleep.
So yes, how much you sleep matters. But how well you sleep matters too.
Sleep apnoea is a particularly good example of this.
With obstructive sleep apnoea, your airway repeatedly becomes narrowed or blocked while you're asleep, causing breathing interruptions. These events can cause brief arousals and changes in oxygen levels, even if you don't fully wake up and have no idea they're happening.
So you might technically be in bed for seven or eight hours, but your sleep is being disrupted again and again. Over time, this kind of fragmented sleep can affect things like attention, concentration, memory and other aspects of cognitive function. This is one of the reasons treating sleep apnoea is about much more than stopping snoring or feeling less tired during the day.
And by the way, how much sleep you need is individual. Not everyone needs the same amount and there is no average that really makes much sense because all the studies that have been done on multitudes of people do not take into consideration the differences and the variety of issues that those people had with their sleep. But that is a topic for another day!
So what does sleep have to do with Alzheimer's?
The connection between sleep and Alzheimer's is particularly interesting because the changes associated with Alzheimer's can begin many years before a person notices any symptoms.
This doesn't mean that poor sleep causes Alzheimer's disease, and it would be too simplistic to say that getting better sleep will prevent it. The relationship appears to be more complicated and may work in both directions. Changes occurring in the brain during the early stages of Alzheimer's can affect sleep, while disrupted sleep may also influence some of the processes associated with the disease. National Institute on Aging: Does Poor Sleep Raise the Risk of Alzheimer's Disease?
What this does tell us is that sleep is worth paying attention to as part of long-term brain health, not just because it affects how you feel the next day. We can't control every factor that influences our risk of cognitive decline, but sleep is one thing we can do something about. If your sleep is consistently poor, fragmented or disrupted, it's worth understanding why and doing something about it.
Give your brain the sleep it needs
It's easy to think of sleep as the time when your body and brain switch off for the night.
But that's not really what's happening.
While you're asleep, your brain is processing information, supporting memory and learning, helping regulate emotions and carrying out important maintenance processes. We're still learning more about exactly how all of this works, but we already know enough to understand that sleep is an important part of keeping your brain healthy and functioning well.
So if you're consistently waking unrefreshed, struggling with your memory or concentration, waking frequently during the night, or experiencing snoring or disrupted breathing, don't just assume you need to try harder to get more hours in bed.
Sometimes the problem isn't that you're not sleeping enough.
It's that your brain isn't getting the sleep it needs.
~ Nina
Sleep Consultant | CPAP Specialist
Sleepin' the Dream
Is poor sleep affecting your life?
If poor sleep is affecting more than just how you feel in the morning. If you’re struggling to concentrate, losing motivation, feeling constantly exhausted, becoming more irritable, withdrawing from the things you enjoy or simply not feeling like yourself anymore - it’s time to take it seriously.
You shouldn’t have to organise your life around being tired or just accept that this is how things are now.
If poor sleep is getting in the way of the life you want to live, I can help. Book your free call to discuss what’s happening with your sleep and whether I can help you get things moving in the right direction.
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