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    How Did You Sleep

    June 21, 2024
    Everything we do, we do better after a good night’s sleep. But are we getting enough sleep and what steps can we take to improve our sleep quality?

    Why sleep matters

    Sleep is vital to our health and lack of sleep can lead to health problems or make existing conditions worse. In the UK, 51% of adults report sleeping less than 6 hours per night and 50% describe their sleep as poor quality [1]. Consistent lack of sleep significantly increases the risk of diabetes, high blood pressure and obesity, and predisposes to poor mental health [2][3].

    In addition, sleep is essential to maintaining concentration, productivity and safety whilst driving. Sleep deprived drivers have similar mental impairment to drunk drivers; 24 hours without sleep has a greater impact on driving performance than a blood alcohol concentration of 50mg/100ml (Scottish drink-drive limit) [4] and many people are killed or seriously injured each year after falling asleep at the wheel [5].

    [2] Infographic from Sleep Foundation (published March 2022)

    How much sleep do we need?

    Most adults need between 7 – 9 hours of sleep per night to maintain health and optimal mental function. Older adults need the same amount but may experience an initial 3–4 hour period of deeper sleep, followed by a period of lighter sleep. Teenagers and children need even more sleep, sometimes as much as 12 hours or more to perform at their best [6].

    A single night of reduced sleep will make you feel tired the next day, but it won’t harm your health. However, after several nights of poor sleep, you are likely to feel a consistent lack of energy, slowed thinking, irritability and difficulty concentrating. Repeatedly missing out on sleep can also leave you vulnerable to depression and anxiety, as well as the physical health issues previously mentioned [7].

    Sleep quality matters too

    The quality of our sleep is almost as important as the number of hours we spend in bed. For example, a person who sleeps for eight hours but wakes many times in the night may still have insufficient sleep, despite the duration of sleep being adequate. We can improve our sleep quality by ensuring our bedroom environment is optimised (not too hot, cold or noisy) and by establishing a routine around bedtime, making sure we spend time winding down before actually going to bed.

    Winding down involves reducing the amount of mental and physical activity we do in the hours immediately before going to bed. Too much mental activity means that our minds continue to race after going to bed, and too much physical activity will result in elevated adrenaline levels which can also keep us awake.

    Reducing screen time and ambient light levels prior to sleep is also important, as this allows maximum melatonin production in the brain, a natural chemical (neurotransmitter) that aids sleep. We suggest shutting off all screens and doing something relaxing, like reading a book, listening to music or taking a bath, at least one hour before your planned bedtime.

    How sleep works - Sleep stages, cycles, REM & non-REM sleep

    During a full night’s sleep, our bodies cycle through five stages of sleep, multiple times. There are four stages of ‘non-REM’ sleep, followed by one stage of ‘REM sleep’. REM stands for Rapid Eye Movement. During REM sleep our eyes move rapidly under our eyelids, but don’t send any visual information to the brain, whereas this doesn’t happen during non-REM sleep.

    Each cycle through all five stages of sleep takes between 90 – 120 minutes to complete. With each subsequent cycle, we spend increasing periods of time in REM sleep, with most REM sleep occurring in the latter half of the night [8] [9]. The infographic below outlines the sleep cycles during a typical 8-hour night’s sleep.

    [10] Infographic from Why We Sleep by Matthew Walker (published Feb 2019)

    REM & non-REM sleep for good health

    Both REM and non-REM sleep are important for health because each serves a different physiological function. When we first fall asleep, non-REM sleep begins, comprising stage 1 (awake/light sleep), stage 2 (light sleep) and stage 3/4 (deep sleep).

    The deep sleep stages of non-REM sleep are especially important because our bodies repair and regrow damaged tissues and strengthen the immune system during this phase. As we age, we naturally tend to sleep more lightly and spend less time in deep sleep, although research shows that we still need a similar amount of sleep as when we are younger [8][9].

    REM sleep (stage 5) follows non-REM sleep, usually starting around 90 minutes after falling asleep, with each subsequent cycle of REM sleep becoming longer (see infographic). REM sleep is commonly associated with dreaming (although dreaming can also occur in non-REM sleep), but it is also vital for memory consolidation, emotional processing, brain development and wakefulness preparation [11].

    Because most REM sleep occurs later in a full night’s sleep, people who don’t get sufficient hours or quality of sleep, can struggle to get enough REM sleep and are therefore deprived of its many benefits. There are also several sleep disorders associated with abnormal REM sleep, including narcolepsy, sleep apnoea and nightmare disorder (see below for more on sleep disorders).

    To read more about the different stages of sleep and their functions, please see the Sleep Foundation’s useful guide here.

    How to improve your sleep

    Poor sleep has multiple causes but is most often linked to lifestyle and our behaviours around bedtime, collectively known as ‘sleep hygiene’. Research consistently points to several concrete steps that promote better sleep, and whilst doing all these steps might seem overwhelming, implementing even one of them will likely improve your sleep. Working towards better ‘sleep hygiene’ can greatly improve the likelihood of consistent, restful sleep.

    Top 10 tips for improving sleep

    1. Optimise your sleep environment – make sure your bedroom is not too hot, cold or noisy. Ensure your bed is comfortable and supportive. If noise is a problem in your neighbourhood, try using some white noise to mask external sounds (available via most online music platforms)

    2. Build positive associations with bedtime – if you associate your bedroom with sleeping, you’re more likely to sleep well. Aim to use the bedroom for sleeping and sex only.

    3. Establish a routine – aim to get to bed and wake up at the same time every day (ideally at weekends too). This helps your internal body clock (circadian rhythm) establish regularity, so that you naturally start to feel sleepy around bedtime.

    4. Reduce screen time – aim to stop all screen usage one to two hours before bedtime.

    5. Relax & wind down – spend time relaxing in the screen-free hours immediately before bed. Read a book, have a bath or shower, or listen to an audiobook, podcast or relaxing music.

    6. Get some exercise – exercise during the day helps you sleep better at night but avoid exercising later than 3 hours before bedtime, as this may interfere with sleep.

    7. Cut caffeine, alcohol & nicotine – avoid caffeine at least 6 hours before bedtime and avoid using alcohol as a sleep aid. Nicotine in any form is a stimulant and will impact sleep, so aim to stop smoking or vaping (we can help you with this).

    8. Write it down – If you regularly find your mind racing at bedtime, it can help to write down your thoughts and worries. Writing yourself a to-do list for the following day can also be helpful.

    9. Seek help – excessive worry, stress, anxiety and depression will all affect sleep. Additionally, thyroid, heart and respiratory conditions can interfere with normal sleep, so consider seeing one of our expert GPs for screening if you’re concerned.

    10. Reset after night-shifts – If you’re work involves night shifts, aim to re-establish your regular sleep routine as soon as possible after a shift. If night shifts are affecting your sleep or your wider mental health, consider changing your working conditions if possible.

    Sleep disorders

    In addition to lifestyle factors and poor sleep hygiene, sleep disturbance can result from clinical sleep disorders. According to the Sleep Foundation, sleep disorders ‘are conditions that affect sleep quality, timing, or duration and impact a person’s ability to properly function while they are awake.

    These disorders can contribute to other medical problems, and some may also be symptoms for underlying mental health issues’ [12]. The commonest sleep disorders are listed below, and you can find out more about each of them via the excellent Sleep Foundation website here.

    Sleep disorders are usually diagnosed by a sleep specialist and may involve undertaking a sleep study, where various physiological parameters are monitored while you sleep. If you’re concerned you may have a sleep disorder, we encourage you to come and see us for an initial consultation with one of our expert GPs, who can work with you to determine the best course of action.

    Common sleep disorders include:

    • Chronic insomnia
    • Sleep apnoea
    • Restless leg syndrome (RLS)
    • Narcolepsy
    • Parasomnias
    • Periodic limb movement disorder
    • Night-time behaviours, such as sleep walking

    The bottom line

    • Sleep is vital to our health & wellbeing, but most people don’t get enough good quality sleep. On average, adults need 7-9 hours of sleep each night.
    • Consistent poor sleep increases our risk of developing physical health conditions including diabetes, high blood pressure, cancer and obesity, as well as mental health problems including depression and anxiety.
    • Sleep is vital to concentration and mental focus, and sleep deprivation is strongly associated with increased risk of accidents, particularly road traffic collisions.
    • Poor sleep is most often due to lifestyle factors and poor ‘sleep hygiene’, which describes our behaviours and routines around bedtime.
    • Good sleep hygiene can greatly improve our chances of regular restful sleep. Our top 10 tips can help improve your sleep hygiene and implementing just one of these strategies is likely to help you sleep better.
    • Physical and mental health conditions, as well as clinical sleep disorders can also impact sleep. Timely diagnosis can improve sleep quality significantly and reduce further conditions or complications developing in future.

    If you would like to discuss how you can improve your sleep or are concerned you may have a sleep disorder, book an appointment with one of our experienced GPs today, or consider undertaking a comprehensive Well Man & Well Woman health check for a comprehensive assessment of your overall health.

    Useful Links

    The Sleep Foundation website -


    Further information about sleep disorders - https://www.sleepfoundation.org/sleep-disorders

    Prof Matthew Walker’s TED Talk entitled Sleep is your superpower.

    - Prof Walker is a Professor of Neuroscience & Psychology at UC Berkley and author of bestselling book ‘Why We Sleep

    Matthew Walker’s TED talk on the stages of sleep, ‘A walk through the stages of sleep


    1. Aviva, "UK adults missing out on 11 hours sleep each week," Aviva, Oct 2018. [Online]. Available: https://www.aviva.com/newsroom/news-releases/2018/10/uk-adults-missing-out-on-11-hours-sleep-each-week/.
    2. Sleep Foundation, "Sleep Deprivation," Sleep Foundation, March 2022. [Online]. Available: https://www.sleepfoundation.org/sleep-deprivation.
    3. C. B. Cooper, "Sleep deprivation and obesity in adults: a brief narrative review," BMJ Open Sport & Exercise Medicine, vol. 4, no. e000392, 2018.
    4. J. Lowrie, "The impact of sleep deprivation and alcohol on driving: a comparative study," BMC Public Health, vol. 20, no. 980, 2020.
    5. Sleep Foundation, "Drowsy Driving," Sleep Foundation, April 2022. [Online]. Available: https://www.sleepfoundation.org/drowsy-driving.
    6. Sleep Foundation, "How much sleep do we really need?," Sleep Foundation, Aug 2022. [Online]. Available: https://www.sleepfoundation.org/how-sleep-works/how-much-sleep-do-we-really-need.
    7. Royal College of Psychiatrists, "Sleeping Well," RCPsych, [Online]. Available: https://www.rcpsych.ac.uk/mental-health/problems-disorders/sleeping-well.
    8. E. Suni, "Stages of Sleep," Sleep Foundation, August 2022. [Online]. Available: https://www.sleepfoundation.org/stages-of-sleep.
    9. S. F. MD, "What are REM and Non-REM sleep?," WebMD, October 2020. [Online]. Available: https://www.webmd.com/sleep-disorders/sleep-101.
    10. Enchiridion, "Book Synopsis: Why We Sleep by Matthew Walker," Enchiridion, [Online]. Available: https://enchiridion.red/2019/2/27/book-synopsis-why-we-sleep-matthew-walker/. [Accessed Sept 2022].
    11. J. Summer, "What is REM sleep and how much do you need?," Sleep Foundation, April 2022. [Online]. Available: https://www.sleepfoundation.org/stages-of-sleep/rem-sleep.
    12. D. Pacheco, "Sleep Disorders," Sleep Foundation, December 2020. [Online]. Available: https://www.sleepfoundation.org/sleep-disorders.

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