Sleep deprivation: How a good night's sleep can impact the brain

Sleep isn’t a luxury—it's a cornerstone of health, alongside diet and exercise, yet it’s often sidelined in our fast-paced world. It is recommended that most adults need between 7-9 hours of sleep per 24 hours, yet a staggering 60% of Australians report not getting adequate sleep. Sufficient sleep is essential for optimal physical health, immune function, mental health, and cognition. So, what happens when we don’t get enough?

What is sleep deprivation?

There are many terms used within the sleep field and it can get confusing. The term sleep deprivation is used by sleep experts to refer to no sleep at all, or a large reduction in sleep, usually lasting one or two days. As the term implies, it involves depriving yourself of sleep (for work or social reasons). 

Other terms such as inadequate sleep, sleep insufficiency, sleep deficiency, sleep disruption and sleep restriction refer to when an individual does go to bed, and does get sleep but it is not enough to support adequate alertness, performance and health. This can be due to just not enough sleep time, or the sleep quality is poor.

Whether you call it sleep deprivation or insufficient sleep, the fact remains that many people are suffering from not getting enough sleep and not really knowing how to improve it. For the remainder of this read,  we’ll use  the term “sleep deprivation” but note that the information refers to both sleep deprivation and sleep insufficiency. Let’s get into the science and tips!

What are symptoms of sleep deprivation/sleep insufficiency?

There are many different signs and symptoms that can have marked negative impacts on our functioning when we’re just not getting enough sleep. These include:

• Reduced alertness and slow reaction times
• Trouble paying attention 
• Reduced cognitive ability and impaired logical reasoning 
• Mood changes, including irritability  
• Anxiety 
• Depression 
• Reduced sex drive 
• Poor judgement 
• Brief daytime sleep periods, called microsleeps 
• Unplanned naps 
• Reduced quality of life 
• Reduced social activity due to tiredness 

What are the effects of sleep deprivation?

Not getting enough sleep can lead to short term effects such as struggling to concentrate, trouble with memory, difficulty paying attention, feeling very irritable, or emotional and of course feeling very sleepy and tired. Reaction times can become reduced and productivity and logical reasoning is reduced. Sleepiness while driving is responsible for many serious car crash injuries and death . Sadly, more than one person per day dies in Australia in car crashes related to insufficient sleep. In older adults, inadequate sleep may be linked to a higher chance of falls and broken bones.

The longer term effects of not getting enough sleep or good enough quality of sleep can contibute to many health problems, including heart problems, mental health problems, some dementias, Type 2 diabetes. Sleep insufficiency may also cause inflammation and reduce the immune system’s ability to fight infections. Short sleep is also linked to obesity, a slower metabolism, and death of any cause.

So, to sum up, the effects are serious.

How to prevent or treat sleep deprivation?

The only way to prevent sleep deprivation is to try and get more sleep. Try to increase the time you allocate to getting enough sleep as this is often a simple strategy that most people overlook. In terms of trying to improve sleep quality and quantity, here are some evidence-based tips:

• Go to sleep and wake up at the same time every day, wherever possible
• Follow a calming bedtime routine every night in the hour or two before bed 
• Avoid using stimulating digital devices before bed and during any nighttime awakenings 
• Only take daytime naps that are shorter than 30 minutes 
• Engage in exercise every day for at least 20 minutes  
• Keep the bedroom dark, cool, and quiet
• Value sleep

Managing sleep deprivation

Despite our best efforts, and because we’re human and often juggling many jobs and responsibilities, there will be times when we feel like we haven’t had enough sleep and need to still get on with our daily activities. So here are some evidence-based tips for those days where you just have to manage your sleepiness and tiredness:

• Don’t drive or operate machinery (or climb ladders!) when you haven’t had enough sleep
• Try to make the most of short naps if you can, to increase your alertness and wellbeing
• Use caffeine in moderate doses to increase your alertness, remember too much and you might not sleep well when you next get your chance!
• Try to remind yourself that this will pass, you won’t feel like this every day
• Eat healthy meals, don’t be drawn in by the sugar cravings that can accompany poor sleep
• Stay as active as you can and get out in the bright natural outdoor light

Summary

Make sleep a top priority in your personal health regimen—it's as crucial as your diet and physical fitness. Embrace it as a vital pillar of wellbeing that you can actively improve with the right knowledge. If you continue to struggle with sleep despite adopting healthier habits over several weeks, consult your healthcare professional for specialised sleep advice.

Related:

• Why do I always feel so tired and what do I do about it?
• What happens when you don’t sleep?
• How to sleep better

Reviewed by Healthylife Advisory Board July 2024