Why Is Sleep Important? The Benefits of a Full Night’s Sleep

Whoever said “you snooze, you lose” was kidding themselves. In fact, sleep is every bit as essential for us as eating, drinking and even breathing properly1.

Believe it or not, 1 in 3 American adults have trouble sleeping. Are you one of them? Getting enough uninterrupted sleep can make a world of difference for your mental and physical health.

But if you’re regularly having trouble getting enough sleep, you’re not alone. It is estimated that between 50 to 70 million people in the U.S suffer chronically from a sleep disorder, which means they can’t get to sleep or stay asleep for very long2. In this guide, we take a look at some of the top reasons why sleep is important, and share our tips on how to get better sleep. Read on to find out more, and set your mind (and body) at rest.

You should talk to your doctor if you have any questions or concerns about your sleep.

How Important Is Sleep?

Getting enough sleep is crucial, as it helps our bodies in several ways, from supporting healthy growth in babies and children, to boosting our physical and mental wellbeing3,4. The amount of sleep you need will depend on various factors, including your age. For example3:

  • Infants (Under two years old) need about 16 hours a day
  • Toddlers and preschoolers (two to four years old) need around 12 hours of sleep a day
  • Teenagers need about nine hours of sleep a night
  • Adults (18 years old and over) need seven to eight hours
  • Pregnant women often need more rest during the first trimester

Of course, this can vary from person to person. Some adults can manage on as little as five hours, while others may need as many as ten3.

Things that might influence this include3:

  • Pre-existing medical conditions people have
  • How physically demanding someone’s days are
  • How much stress they’re under
  • Genetic factors

Find out more about the different stages of sleep, and why they matter too.

Sleep, Depression, and Other Mental Health Issues

A lack of sleep affects many ‘cognitive functions’ – which are our mental abilities, and how we think and reason. Sleep deprivation can impact our memory, performance and even our ability to plan clearly. If you become severely sleep-deprived, you may even experience mood swings and, in some cases, hallucinations3.

Sleep is a key part of maintaining good mental health. In fact, a lack of sleep can be linked to a number of issues, including5 :

  • Trouble concentrating or staying focussed
  • Triggered mania or paranoia
  • Increased risk of depression, anxiety or suicidal behavious.

Talk to your doctor and/or another qualified professional if you have questions or concerns about your mental health.

Sleep, Weight loss, and Physical Health

Not having enough sleep can have far-reaching effects on our physical health too. Regularly missing out on sleep could increase your risk of several health conditions, including3:

  • Obesity
  • Diabetes
  • Stroke
  • Heart problems
  • 15% more likely to develop or die of a stroke

A lack of sleep could even impact our immune systems, making us more susceptible to common illnesses such as colds and flu3.

Health Benefits of Sleep

Considering the impact a lack of sleep can have on the human mind and body, it’s not surprising that – by contrast – getting plenty of good-quality sleep can be really fantastic for our physical and mental well-being. So the good news is there are many benefits of sleep.

Better concentration and memory

When we sleep, our nerve cells have a chance to repair themselves so that they function at their best. This can help strengthen our brains and improve our ability to think clearly3,9.

If you’re studying at college or doing lots of training at work – take note! It’s vital you get a good night’s sleep when you’re trying to take in new information, as we’re more able to process and retain information when we’re well rested7.

Helps repair and heal

During a phase of sleep known as non-rapid eye movement (Non-REM), your body builds muscle, repairs tissue and boosts its immune system – great after a challenging workout, and for helping aches and pains3.

This is why it’s so important to effectively manage pain at night, such as back pain or leg pain, as it can lead to what some patients have begun to call ‘painsomnia’.

If you’re finding your minor aches and pains stop you from getting some much-needed rest, you can try over-the-counter sleep and pain relief options. TYLENOL® PM**, for example, helps you fall asleep faster*.

Be sure to always read and follow the product label of the OTC pain reliever and talk to your doctor if you have any questions or concerns.

**TYLENOL® PM contains a pain reliever and nighttime sleep aid.
*than placebo/vs no treatment

Improved mood

That link between sleep and mental health – especially depression – really can’t be ignored. Have you ever noticed that you wake up feeling rested and in a much better mood when you sleep well?

Researchers have found that daily sleep quality and a person’s mood are closely related, so the science seems to bear that out too8.

Better physical performance

Sleep can help improve all types of exercise performance. Getting proper rest means the neurons in our brains can recover their energy so that they can perform at their best, keeping the muscles and organ systems in sync with one another.

Getting enough sleep regularly can therefore help improve your8:

  • Muscle strength10
  • Reaction times11

What is Sleep Deprivation?

Simply put, sleep deprivation is when you’re not getting enough sleep to function properly3.

However, while how long you sleep definitely matters, being well-rested is more dependent on the amount of quality or undisturbed sleep you get. So, you could sleep for eight hours, but if you wake up several times during that time, you could still end up experiencing sleep deprivation9.

It can usually be split into three different categories12:

  • Acute sleep deprivation: a short period of a few days or less, when you get significantly less sleep
  • Chronic sleep deprivation: also known as ‘insufficient sleep syndrome’, which is defined as impaired sleep lasting three or more months
  • Chronic sleep deficiency or insufficient sleep: ongoing sleep deprivation caused by sleep fragmentation or other disruptions

Signs of Sleep Deprivation3

If you experience these symptoms, you may well be affected by sleep deprivation:

  • Falling asleep almost immediately after lying down
  • Feeling sleepy during the day
  • Nodding off for short periods during the day when you’re otherwise awake – this is known as ‘microsleep’

Common Causes of Sleep Deprivation3

Medical problems

Various health conditions can impact our ability to sleep well, and end up causing sleep deprivation. For example, arthritis and other conditions that cause aches, pains and discomfort can make it harder to fall asleep13.

Over-the-counter extra strength products like TYLENOL® PM can help ease those minor aches and pains so you can drift off to a pleasant sleep.

Sleep deprivation could also be a symptom of an underlying sleep disorder or mental health condition, such as12,14:

  • Sleep apnea
  • Depression
  • Anxiety disorders


Sleep deprivation can occur as a result of your day-to-day lifestyle. For example, you may get less sleep if you’re woken in the night by children, or an elderly relative you care for.

If you have irregular working hours or stay up late at night to watch TV or read, you may find that this also impacts how well you sleep.


Short-term or acute sleep deprivation can be caused by life stresses such as15:

  • Work stress
  • Family disagreements
  • Grief
  • Illness


Not having the right sleeping environment can also cause sleep deprivation. This could include a room that is too bright, too hot or cold, or too loud15.

Investing in a comfortable bed and mattress, and managing light levels, noise levels and temperature effectively, could make all the difference.

Tips on How to Sleep Better

Fortunately, there are some useful things you can do to help, if you’re struggling to get to sleep at night.

Manage pain

Managing minor aches and pains with over-the-counter products can help remove one of the barriers to a good night’s sleep, by easing your discomfort and helping you fall asleep.

Rest and relax16

Try to take some time to relax your mind and resolve your worries before you head to bed for the night. You could try writing your thoughts down in a journal or taking some time to meditate.

Some people find that preparing for the following day and setting their priorities can help ease stress and anxieties too. This is especially useful if a lack of sleep is contributing to depression or other mental health concerns.

Set a sleep schedule16

Practice good sleep routines by setting yourself a regular schedule. This means going to bed and getting up at the same time every day – even on weekends. If you need some variation, try to keep it to no more than one hour each side for going to bed or getting up.

Creating this consistency can help reinforce your body’s natural sleep-wake cycle.

If you’re still awake after 20 minutes of settling down for the night, try getting up and doing something relaxing like meditating, reading or listening to soothing music or a sleep podcast. Head back to bed when you start to feel tired again. Repeat as many times as necessary.

Manage your diet16

Try not to go to bed hungry, or feeling over-full. It’s best to avoid eating a large meal within a couple of hours of heading to bed, as this could cause discomfort and indigestion, which might keep you up.

Steer clear of caffeine, nicotine, and alcohol in the hours before bed too, as these can all stimulate the brain and make it difficult to fall asleep.


Keeping up with regular physical activity can help you sleep better, so walking, running or cycling each day – even if you don’t head to the gym – can be a great thing.

Just make sure you avoid being too active close to bedtime!

Be sure to talk to your doctor before starting or changing any exercise regimen.


When you get your recommended eight hours of sleep really does matter. It’s better to get as much sleep as possible when it’s dark, because this helps synchronize your body’s natural circadian rhythm with the environment17.

Napping during the day has both pros and cons. Whether it’s right for you depends on a variety of factors. For example, a quick power nap in healthy adults can help combat fatigue and low moods. However, some adults find that taking a nap during the day can impact their ability to sleep at night18.

Toddlers and young children often need more sleep to aid their growth, so naptimes should be built into their daily routine3.

Typically teenagers do need more sleep than fully grown adults3. In fact, getting enough sleep can help teens retain and process new information during their studies, which is vital to their education and social development7. So, if they’re sleeping less than the recommended nine hours a night, this is worth bearing in mind.

Related content


1. Division of Sleep Medicine at Harvard Medical School. https://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/why-do-we-sleep

2. ASA American Sleep Association. How Important Is Sleep? https://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/why-do-we-sleep

3. Centers for Disease Control and Prevention. 1 in 3 adults don’t get enough sleep. https://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html

4. Division of Sleep Medicine at Harvard Medical School. http://healthysleep.med.harvard.edu/healthy/matters/consequences/sleep-and-disease-risk

5. How to cope with sleep problems. https://www.mind.org.uk/information-support/types-of-mental-health-problems/sleep-problems/about-sleep-and-mental-health/

6. Cappuccio FP, Cooper D,D’Elia L, Strazzullo P, Miller MA. Sleep duration predicts cardiovascular outcomes: a systematic review and meta-analysis of prospective studies. Eur Heart J. 2011;32 (12):1484-1492.

7. Division of Sleep Medicine at Harvard Medical School. https://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep

8. Triantafillou S, Saeb S, Lattie EG, Mohr DC, Kording KP. Relationship Between Sleep Quality and Mood: Ecological Momentary Assessment Study. JMIR Ment Health. 2019;6(3):e12613. Published 2019 Mar 27

9. Division of Sleep Medicine at Harvard Medical School. https://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/learning-memory

10. Chen Y, Cui Y, Chen S, Wu Z. Relationship between sleep and muscle strength among Chinese university students: a cross-sectional study. J Musculoskelet Neuronal Interact. 2017 Dec 1;17(4):327-333. PMID: 29199194; PMCID: PMC5749041.

11. Sleep, Athletic Performance, and Recovery. https://www.sleepfoundation.org/physical-activity/athletic-performance-and-sleep

12. Sleep Deprivation. https://www.sleepfoundation.org/sleep-deprivation

13. Why sleep is important. https://www.apa.org/topics/sleep/why

14. Sleep Deprivation. https://aasm.org/resources/factsheets/sleepdeprivation.pdf

15. Karna B, Gupta V. Sleep Disorder. [Updated 2021 Nov 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560720/

16. Sleep tips: 6 steps to better sleep. https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/sleep/art-20048379

17. Jagannath A, Taylor L, Wakaf Z, Vasudevan SR, Foster RG. The genetics of circadian rhythms, sleep and health. Hum Mol Genet. 2017;26(R2):R128-R138. doi:10.1093/hmg/ddx240.

18. Napping: Do’s and don’ts for healthy adults. https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/napping/art-20048319