The role of sleep in mental and physical health

Sleep – something many of us aren’t getting enough of! A good night’s sleep helps your brain to reset and process the information you’ve learned during the day. It’s also time for your body to rest and repair itself. But not getting enough sleep can have a serious impact on your physical and mental wellbeing. Let’s talk about why sleep is so important, what happens if you don’t get enough, and discuss a few ways to get more, better quality sleep.

The Science of Sleep

Much like eating and drinking, sleep is an important body function that’s necessary to keep us alive and healthy. You spend about one third of your life asleep, but many of us aren’t getting the 7-9 hours a night that we need. Sleep is linked to many normal bodily functions and can affect your:

• Hormones
• Blood pressure
• Heart and lungs
• Metabolism
• Immune system

But how does your body know when to sleep in the first place? Your brain has an internal clock known as the circadian clock that tells you it’s time to sleep. Everyone’s internal clock is slightly different, and external factors like light levels can also affect it. When you become sleepy and start falling asleep, your brain goes through several different stages of sleep. This can be roughly broken down into two different types: rapid eye movement (REM) and non-rapid eye movement (non-REM) sleep.

Non-REM Sleep

Non-REM sleep can be further divided into three stages.

Stage 1 – You’ll move into the first stage of non-REM sleep first as your brain activity changes from its awake state to being asleep. This usually lasts several minutes.

Stage 2 – A lighter type of sleep where your breathing slows, body temperature drops, and you progress into deeper sleep.

Stage 3 – Deeper sleep where you may be difficult to wake up. This type of sleep is what leaves you feeling refreshed in the morning.

Rapid eye movement sleep usually happens in the first hour or two after you fall asleep. This stage of sleep is where most of your dreams happen and you may breathe quickly or more irregularly.

REM Sleep

Both REM and non-REM sleep are necessary to get the full benefits of sleep, although we don’t know exactly why. Some studies suggest that REM sleep helps to consolidate what you’ve learned in the day into memories and is important for brain development when you’re young. Non-REM sleep may be more important for the body to physically repair itself and to support the immune system.

Almost every organ and tissue in the body is impacted by sleep, so it makes sense that lack of sleep can lead to a whole host of health problems.

Poor Sleep and Physical Health

We already talked about how important sleep is for your body to rest and repair. Let’s discuss some of the things that can go wrong if you’re not getting enough.

Worse Cardiovascular Health

During non-REM sleep, your blood pressure and heart rate fall which means your heart doesn’t have to work as hard as it does when you’re awake. If you’re not getting enough sleep (especially non-REM), or if you’re waking up often throughout the night, you may be at increased risk of heart disease, strokes, and high blood pressure

Impaired Metabolism

The way your body’s metabolism works varies throughout your circadian cycle (otherwise known as the sleep-wake cycle). Not getting enough sleep can disrupt hormone levels related to hunger, reduce your body's sensitivity to insulin, and lead to a condition known as metabolic syndrome (which can increase your risk of heart disease and diabetes).

Hormonal Changes

As the way your body releases hormones is related to your circadian cycle, poor or disrupted sleep can disrupt normal hormone production in the body. This can impact hormones like cortisol and melatonin that help control your sleep, sex hormones like testosterone and oestrogen, and hormones that control blood sugar and hunger levels.

Issues with Your Immune System

Sleep is essential for maintaining good immune function. The immune system works differently during different parts of the circadian cycle, and disruption of the cycle can lead to increased levels of inflammation as the immune system is unable to regulate itself properly. This can lead to inflammatory diseases and increase the likelihood of catching an infection.

Now we’ve talked about the ways poor sleep affects your physical health, let’s dive into how it impacts your mental health and mood.

Poor Sleep and Mental Health

Sleep and mental health are closely connected. When you sleep, your brain processes information, thoughts, and feelings from the day. If you’re not sleeping enough, your brain may not have time to process all this information, which can negatively impact your mood.

In fact, poor sleep can increase your risk of experiencing anxiety, depression or other types of mental health issues. Interestingly, the relationship goes the other way too, as a mental health disorder may also increase the risk of sleeping poorly or experiencing insomnia.

Lack of sleep doesn’t just impact emotional regulation and mood – it also affects memory, concentration and decision making. This can have all kinds of consequences on someone’s daily life.

How Poor Sleep Affects Your Wellbeing

Sleeping well helps refresh you and prepare you for the day. However, not getting enough of it can make it harder to concentrate at school or work. This may mean you make more mistakes or can’t complete tasks to your best ability.

If lack of sleep is affecting your mental health, you may find it harder to manage your stress levels or struggle with mood swings, irritability, or anxiety. This can affect your relationships with your loved ones or work colleagues.

Your energy levels may also be affected, reducing your motivation to exercise. When you’re tired, you’re also more likely to reach for unhealthy drinks and snacks and to eat more in general.

Long-term, both lack of sleep and behaviors relating to tiredness can lead to physical health problems like frequent coughs and colds, weight gain and chronic diseases. Although this sounds scary, the good news is you can do plenty of things to avoid this.

But before we get into how you can improve your sleep, let’s talk about how much you should actually be getting.

Am I Getting Enough Sleep?

The NHS recommends between 7-9 hours of sleep for a normal, healthy adult. However, everyone’s circadian clock is unique, and this is a general figure to aim for. You may need more depending on your age, health, and other personal circumstances.

Babies, children, and teenagers usually need more sleep as they’re still growing and developing.

It can be difficult if you’re struggling to get enough sleep, but luckily there are lots of things you can do to improve both the quantity and the quality of your sleep.

Tips for Improving Your Sleep

People sleep badly for different reasons. In some cases, a health condition like sleep apnoea is involved which may require advice from a healthcare professional.

For many people, stress and worries can impact their sleep. Finding healthy ways to destress before bed can help, whether that’s meditation, yoga, breathing exercises, journalling, or something else that works for you.

Regular physical exercise has also been shown to help people manage their stress better. Even if you’re not feeling stressed, studies suggest exercise can help people with sleep disorders and improve sleep quality. Try to add some type of exercise into your daily routine if you can.

Finally, it’s important to think about your bedtime routine. This means establishing a regular sleep schedule where you go to bed and wake up at the same time. Try to limit screentime in the hour leading up to bed and avoid stimulants like caffeine.

Make sure the room you’re sleeping in is dark, quiet, and not too hot or cold. You may find music or white noise helpful when you’re trying to drift off.

Everyone is different, so you may need to try a few different things before you figure out what works best for you.

Sleep is essential for your health and wellbeing, and sleeping poorly can take a real toll on your hormonal, cardiovascular, immune, and mental health. Making some changes to your lifestyle and bedtime routine can be really effective, but if you’re still struggling to get enough sleep it’s best to speak to a healthcare professional

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