Sleep is a big part of the human experience – ideally, we spend about one-third of our lives asleep. But did you know that scientists still haven’t come to a consensus on its biological function? Read ahead to learn the fascinating science of sleep and find out how it affects your health and wellbeing.
In this guide, we will cover the following:
- What is sleep?
- Why do we sleep?
- Why is sleep important?
- What happens if you don’t sleep?
- How many hours of sleep to adults need?
- How many hours of sleep do the elderly need?
- How many hours of sleep do children need?
- How to sleep better
- What to do if you can’t sleep
- The different stages of sleep
- How much deep sleep you need
- Common sleep problems
- Incontinence and sleep
- How to Get Help with Sleep Problems
- Treatments for sleep problems
What is Sleep?
You do it every day – but what exactly is sleep?
Sleep is just as vital to your health as food and hydration. It helps you form new neural connections, form memories, concentrate on topics, and quickly respond to stimuli. It’s one of the most important things that we do. For an average of six to eight hours each night, we lay down and ‘shut down’ our minds, closing our eyes and resting.[i] Our breathing slows, our body temperature drops, and our cells renew and regenerate.
Why Do We Sleep?
While sleep is integral to everything we do, scientists are still unsure of its biological purpose. However, most researchers believe it allows our brains and bodies to regenerate and recover.
As we experience new things throughout the day, our brains don’t fully process all of the information right away. As we sleep, our brains process and make connections about these experiences. The important information is strengthened and stored, and the inconsequential things are forgotten.
Why Is Sleep Important?
Sure, a lack of sleep can make you feel grumpy, but why is it so important?
As mentioned above, chronic sleep deprivation increases your risk of serious medical issues, including diabetes and heart disease, and it decreases your life expectancy. Simply put, you need sleep to live a long, happy, and healthy life.[ii]
- It improves your immune system – If you get an adequate amount of sleep, you’re less likely to catch viruses and feel ‘run down.’
- It regulates your weight – Research has shown that people who lack restful sleep have reduced levels of leptin, the hormone that makes you feel satiated and full.
- It improves your mood – A chronic lack of sleep can lead to anxiety, depression, and a general low mood.
- It boosts your libido – Research shows that both men and women who get enough rest show more interest in sex.
- It protects your heart health – People with chronic sleep deprivation experience a quicker heart rate and higher blood pressure, which strain the heart.
- It improves fertility – A chronic lack of sleep can affect reproductive hormones in both men and women.
What Happens If You Don’t Sleep?
While the occasional ‘all-nighter’ won’t permanently harm your health, chronic sleep deprivation can cause severe health problems. A chronic lack of sleep (fewer than six hours per night) has disastrous effects on health. It increases your risk of many health issues, including depression, obesity, cardiovascular disease, diabetes, and high blood pressure.
If you don’t sleep for 24-36 hours, you’ll feel exhausted, irritable, and start to become delirious. After three days, you begin to hallucinate. After this point, you will likely begin to experience psychosis and erratic mood swings.
How Many Hours of Sleep Do Adults Need?
There is no one answer to the question “how much sleep do I need?” Everyone’s sleep needs vary, based on their activity levels, overall health, and personal preference. According to Harvard Health, the National Sleep Foundation recommends between seven and nine hours of sleep each night for people between the ages of 18 and 64.[iii] Children need more sleep, while older adults need slightly less.
Of course, it’s important to remember that these recommendations are based on averages. Some nights you may get more rest, while others you may get less. When assessing your sleep, be sure to take an average over a week or even a month.
- Is 6 Hours of Sleep Enough?
While six hours of sleep could be just enough to prevent you from feeling groggy and irritable the next day, don’t make it a habit. Studies show that getting fewer than six hours of sleep each night can more than double your chances of dying from heart disease and cancer.[iv]
- Is 7 Hours of Sleep Enough?
While it is on the lower end of the recommendations, seven hours of sleep is likely enough for most adults. However, you should base your sleep on your own personal needs and how you feel.
How Many Hours of Sleep Do the Elderly Need?
The National Sleep Foundation study cited above recommends that people above the age of 65 get between seven and eight hours of sleep each night.
How Many Hours of Sleep Do Children Need?
According to the NHS, children’s sleep needs change as they grow.[v] Here are the recommended hours of sleep for different age groups:
- 4 to 12 months – 12 to 16 hours, including naps
- 1 to 2 years old – 11 to 14 hours, including naps
- 3 to 5 years old – 10 to 13 hours, including naps
- 6 to 12 years old – 9 to 12 hours
- 13 to 18 years old – 8 to 10 hours
How You Can Sleep Better
Try these tips to help you sleep better.[vi]
- Stick to a sleeping pattern – Try to keep to the same sleep schedule every night, even on weekends. Going to bed and waking up at the same time every day can help to condition your brain.
- Don’t sleep longer than eight hours – While you might be tempted to ‘catch up on sleep,’ eight hours per night is enough to recharge and refresh.
- Don’t stay in bed if you can’t sleep – If you are having trouble falling asleep after more than 20 minutes of lying in bed, get up and do something calm and quiet. Read a book, meditate, or listen to calming music. Only get back into bed when you are tired.
- Say goodbye to screens – Keep screens out of the bedroom – their blue light can interrupt your sleeping patterns.
- Don’t eat a heavy meal before bed – Being too full after a heavy meal can make you feel lethargic, but can actually prevent you from falling asleep.
- Avoid alcohol – While alcohol can help you ‘pass out,’ you will usually wake up three to four hours after falling asleep, and you won’t be able to get back to sleep.
- Don’t nap during the day – While napping can be tempting, they can prevent you from getting a good night’s sleep.
- Get more exercise – By getting more physical activity during the day, you can improve your sleep habits and fall asleep more easily.
What to Do If You Can’t Sleep
It can feel very frustrating when you can’t get to sleep. Try some of these techniques and tips to help you get some rest.[vii]
- Remove all devices – Smartphones and iPhones emit ‘blue light,’ which sends a message to your brain that it is daylight. Try not to use any devices for two hours before bedtime.
- Keep things quiet or soothing – Jarring sounds or repetitive sounds (such as a dripping faucet) can keep you awake. Consider soothing music or meditative podcasts.
- Calming scents – Some people find the scent of lavender to be very soothing, helping them to feel drowsy.
- Avoid big meals – Don’t eat a big meal or heavy snacks in the few hours before bed.
- Keep the room cool – Though it may seem counterintuitive, you’ll have an easier time falling (and staying) asleep in a cool room.
What Are the Different Stages of Sleep?
Scientists have identified four different stages of sleep.[viii] In the past, these were thought to be five distinct stages, but stages three and four have now been combined.
We move through these four stages during each sleep cycle, which usually lasts between 90 minutes and 110 minutes.
- Stage 1 (non–REM) – This stage lasts around 10 minutes, and occurs between wakefulness and sleep. During this stage your heartbeat, eye movements, and breathing slows.
- Stage 2 (non-REM) – Stage 2 is a light sleep stage that lasts around 20 minutes. Your brain waves become rhythmic and rapid.
- Stage 3 (non-REM) – Stage 3 is the final non-REM stage. During this 20 to 40-minute stage you sink into a deep sleep.
- REM sleep (Stage 4) – Approximately 90 minutes after Stage 1, you sink into the deepest sleep in which your heartrate and breathing slow to their lowest levels. REM stands for ‘Rapid Eye Movement,’ which occurs as you dream.
How Much Deep Sleep Do You Need?
While all stages of sleep are important, scientists agree that deep sleep is crucial for health and wellbeing. Without deep sleep, you simply won’t feel well-rested.[ix] Most healthy adults get between one and two hours of deep sleep per eight hours of sleep.
Common Sleep Problems
The issues listed are just some of the most common sleep problems.[x]
- Nocturnal Enuresis – Nocturnal enuresis occurs when a person urinates involuntarily during the night. While many people associate ‘bedwetting’ with young children, this is a common problem amongst older adults and those with disabilities. Incontinence pads for men and incontinence pads for women can both be used to help sufferers and their bedding stay clean and dry throughout the night. Bed protection such as Bed Mats can also be used as an added level of security if you’ve concerned about leakages.
- Sleep Paralysis – Sleep paralysis occurs in stage 1, and essentially paralyses the sufferer. It may be accompanied by vivid ‘waking dreams.’ Though sleep paralysis is harmless, it can be extremely frightening.
- Sleep Apnoea – Sleep apnoea, when your breathing stops and starts during sleep, occurs during stage 1.[xi] It is common in obese individuals, and can be treated with a CPAP machine that helps you breathe as you sleep.
- Restless Legs Syndrome – Restless legs syndrome(RLS) causes an urgent and unsettling feeling that you must move your legs when laying down or sitting. There is no known cause, although low iron levels may be correlated.
- Insomnia – Insomnia is a condition that prevents you from getting to sleep or staying asleep. It is often accompanied by depression, irritability, and low energy.
Incontinence and Sleep
People who suffer from bladder weakness and incontinence can often have trouble sleeping as they lay in bed worrying about having an accident, or leakages in the night. If an accident does occur, sleep is broken cleaning and changing clothing and bedding. MoliCare® has a wide range of pads, pants and bed protection for all levels of bladder weakness, urine and faecal incontinence. Choosing a higher absorbency product at night will securely contain urine throughout the night and the Quick Dry System will leave the skin feeling dry throughout the night.
How to Get Help with Sleep Problems
If you have any problems with your sleep, including sleep apnoea, RLS, or chronic insomnia, your first point of contact should be your GP. They can recommend techniques and treatments, and refer you to a specialist, if necessary.
Treatments for Sleep Problems
Your GP will work with you to discover the source of your sleep problem, and will refer you onto a specialist if necessary.[xii] If you are experiencing insomnia, they may refer you on to a therapist for cognitive behavioural therapy (CBT). Sleeping pills are often used as a last resort, as they can have serious side effects and cause addiction. You may receive a short-term prescription for sleeping pills if you have severe insomnia and other treatments have been unsuccessful.
FAQs About Sleep
- How to Get to Sleep Fast?
It’s a cruel irony that watching the clock and worrying about falling asleep will often cause you to toss and turn! To get to sleep fast, we recommend a guided sleep meditation. There are some great apps out there that can guide you into a deeply relaxed state.
- How Long Can You Go Without Sleep?
The longest recorded time with no sleep is 264 hours, which is around 11 full days.[xiii] After just two or three days with no sleep, you’ll start to hallucinate and experience extreme emotions, cognitive impairment, and psychosis, and delusions. While sleep deprivation rarely causes death, it can happen.
- How Many Calories Do You Burn Sleeping?
Did you also know that you burn calories even when you sleep?[xiv] It’s true – you’ll burn an average of 250 – 350 calories each night during 7 – 9 hours of sleep.
Ghosh, P. (2015). Why do we sleep? BBC News. [online] 14 May. Available at: https://www.bbc.co.uk/news/science-environment-32606341 [Accessed 18 Dec. 2020].
Harvard Health Publishing (2019). How much sleep do we really need? – Harvard Health. [online] Harvard Health. Available at: https://www.health.harvard.edu/staying-healthy/how-much-sleep-do-we-really-need [Accessed 18 Dec. 2020].
Leavitt, J. (2018). How Much Deep, Light, and REM Sleep Do You Need? [online] Healthline. Available at: https://www.healthline.com/health/how-much-deep-sleep-do-you-need#takeaway [Accessed 18 Dec. 2020].
Mayo Clinic Staff (2017). 6 steps to better sleep. [online] Mayo Clinic. Available at: https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/sleep/art-20048379 [Accessed 18 Dec. 2020].
National Institute of Neurological Disorders and Stroke (2019). Brain Basics: Understanding Sleep | National Institute of Neurological Disorders and Stroke. [online] Nih.gov. Available at: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep [Accessed 18 Dec. 2020].
NHS Choices (2019a). How much sleep do children need? [online] NHS Choices. Available at: https://www.nhs.uk/live-well/sleep-and-tiredness/how-much-sleep-do-kids-need/ [Accessed 18 Dec. 2020].
NHS Choices (2019b). Insomnia. [online] NHS Choices. Available at: https://www.nhs.uk/conditions/insomnia/ [Accessed 18 Dec. 2020].
NHS Choices (2019c). Less than 6 hours of sleep a night linked to increased risk of early death – NHS. [online] NHS Group. Available at: https://www.nhs.uk/news/lifestyle-and-exercise/less-6-hours-sleep-night-linked-increased-risk-early-death/ [Accessed 18 Dec. 2020].
NHS Choices (2019d). Sleep and tiredness. [online] NHS. Available at: https://www.nhs.uk/live-well/sleep-and-tiredness/why-lack-of-sleep-is-bad-for-your-health/ [Accessed 18 Dec. 2020].
NHS Choices (2019e). Sleep apnoea. [online] NHS. Available at: https://www.nhs.uk/conditions/sleep-apnoea/ [Accessed 21 Dec. 2020].
Ruhl, C. (2020). Stages of Sleep: REM and Non-REM Sleep Cycles | Simply Psychology. [online] www.simplypsychology.org. Available at: https://www.simplypsychology.org/sleep-stages.html [Accessed 18 Dec. 2020].
Suni, E. (2019). What to do When You Can’t Sleep | National Sleep Foundation. [online] Sleepfoundation.org. Available at: https://www.sleepfoundation.org/insomnia/treatment/what-do-when-you-cant-sleep [Accessed 18 Dec. 2020].
The Sleep Council (2019). How Many Calories Do You Burn Sleeping? [online] The Sleep Council. Available at: https://sleepcouncil.org.uk/how-many-calories-do-you-burn-sleeping/ [Accessed 18 Dec. 2020].
Vandergriendt, C. (2018). How Long Can You Go Without Sleep? Function, Hallucination, More. [online] Healthline. Available at: https://www.healthline.com/health/healthy-sleep/how-long-can-you-go-without-sleep#what-happens-after-24-hours [Accessed 18 Dec. 2020].