Blog Mental Health Sleep Is 4 Hours Of Sleep Enough? Here’s What Science Says

Is 4 Hours Of Sleep Enough? Here’s What Science Says

Do you like sleeping? It’s hard to find a person who doesn’t enjoy nice deep sleep. You lie on your bed covered with freshly-cleaned bedding, breath in the relaxing aroma, close your eyes, and drift off.


But this process is not so pleasurable for all people. There are internal and external stressors and responsibilities that can deprive us of good sleep. Some may work night shifts, others might stay awake because their baby is crying the whole night, and others simply could obsess themselves by scrolling compelling videos on the Internet. 

So, instead of 7 or 8 hours, you might sleep only 4 or 6 hours a day. More commonly people wake up during the night to go to the bathroom, have a glass of water, or simply may get sweaty from the hot summer days. This impairs the quality of sleep and the next day you are too weary for even regular activities

But what if you can’t help but sleep only 4 hours per day? Your job takes too much time or other stressors deprive you of the optimal time for sleep. 

Read this article to unravel whether 4 hours of sleep per day is healthy for your body and mind. Is 4 hours of sleep enough? Here’s what science says. 

Can You Survive With 4 Hours Of Sleep?

Think about the last time you slept 4 hours per day. For some people it might be enough. They still feel invigorated enough and ready to commit to their daily tasks. This means – you can survive with 4 hours of sleep everyday. But is it healthy though? 

The National Sleep Foundation gives the following recommendations for the appropriate amount of sleep every day. Here’s what they’re suggesting: 

  • newborns (0–3 months): 14–17 hours
  • infants (4–11 months): 12–16 hours
  • toddlers (1–2 years): 11–14 hours
  • preschool (3–5 years): 10–13 hours
  • school-age kids (6–12 years): 9–12 hours
  • teenagers (13–18 years): 8–10 hours
  • younger adults (18–25 years): 7–9 hours
  • adults (26–64 years): 7–9 hours
  • older adults (65 years and above): 7–8 hours

Sleeping less may be detrimental to your health and mental performance. You can try it out for a few days but gradually you’ll notice the negative effects of it.

Read More: How To Wake Up Early To Work Out And Master The Day With 21 Tips


What Happens If I Sleep 4 Hours?

You need healthy sleep to function well. But sometimes you lack good sleep, even down to 4 hours. No matter whether you’re sleeping for 4 hours per night intentionally or unintentionally, you will end up with a great number of negative 4 hours of sleep effects:

  • mood swings
  • irritable feelings for no reason
  • problems with focusing and remembering
  • fatigue
  • a reduced sex drive (4).
See also
5 Reasons You Should Do A Digital Detox

This is the top of the iceberg as sleep deprivation leads to changes in your body: 

  • The immune system. You will become more prone to infections, which might take longer to resolve, and respiratory diseases (5).
  • Weight. It’s still surprising that you can gain weight during impaired sleep. Here’s how it works: bad sleep affects the hormones responsible for feelings of hunger and fullness. It also triggers the release of insulin. Your lack of optimal sleep range can cause increased fat storage, body weight changes, and a higher risk of type 2 diabetes.
  • The cardiovascular system. Healthy sleep plays a crucial role in heart vessels healing and rebuilding. It helps maintain blood pressure, sugar levels, and inflammation control. If you sleep only 4 hours or less you elevate your chances to the risk of cardiovascular disease.
  • Hormone levels. Your hormone production can change due to insufficient sleep. This includes the production of growth hormones and testosterone. Plus, your body releases additional stress hormones, such as cortisol and norepinephrine.
  • The brain. You sleep less, therefore, impairing your prefrontal cortex, which handles reasoning, and the amygdala, which deals with emotion. In addition to this, it may be harder for you to form new memories, and it affects learning. 
  • Fertility. Not enough sleep may affect the production of hormones that promote fertility (9).

Looking for a way to break the vicious cycle of weight loss and tone up all the jiggly parts? Watch the extra pounds fly off and your muscles firm up with the BetterMe app!

is 4 hours of sleep enough

Is 3 To 4 Hours Of Sleep OK?

It is not okay to sleep only 3 to 4 hours. From the previous segment you’ve learned about the optimal time ranges of sleep for different people. 

Doing it for a short period of time is one thing but practicing short sleep all your life can put you at risk of serious health conditions:

  • heart disease
  • diabetes
  • kidney disease
  • depression (7).

Also, you need to tell the difference between sleep deprivation and insomnia. The first one means you can’t fall asleep no matter how hard you try while sleep deprivation entails consciously not finding time for good sleep.

Therefore, choosing to sleep for only 3 to 4 hours intentionally will impact the quality of your life. You won’t only feel tired but end up with serious health conditions in the future. It’s essential for you to analyze the main reasons why you sleep so little. 

See also
How Should You Sleep To Improve Your Posture? Simple Tips & Tricks

Some daily habits or lifestyle activities can impair your sleep. Some changes can help. But if you frequently have trouble sleeping, contact a healthcare provider for the important guidelines.

Read More: How Should You Sleep To Improve Your Posture? Simple Tips & Tricks

How Much Sleep Is Too Little?

Do you want to get the most out of good sleep? Then you need to sleep the appropriate amount of hours. Still, the optimal time is 7 to 9 hours in adults. But when it becomes too little sleep there is one simple answer – less than 7 hours of sleep is detrimental. 

Your parents have probably made you go to bed at 11 PM for example, so that you could enjoy the full range of 4 sleep phases. 

Getting less than 7 hours of sleep on a regular basis provokes poor health, including high blood pressure, diabetes, depression, heart disease, stroke, and weight gain (1). 

If you sleep too little from time to time, no need to worry as we all know how unpredictable life may be. However, constant lack of enough sleep is negative for your health and mental abilities.

is 4 hours of sleep enough

Is It Healthy To Sleep 4 To 5 Hours?

The short answer is no, sleeping for 4 to 5 hours is not healthy. Some people claim 4-5 or 6 hours is enough for them. But they’re wrong. Here’s the reality, if you sleep for 4 to 5 hours daily you gradually get used to the negative effects of sleep. 

Training your body to sleep less is not a good option as your body needs more sleep than 5 hours. You might be thinking you’re adapting to being awake more but in fact, you are performing daily activities at a lower level. 

Thus, having 4 hours of sleep for a month, year, etc. is not healthy. Try to sleep an adequate amount of hours compatible with your age. 

Is It Okay To Sleep 4 Hours Twice A Day?

Most people sleep in the same way – they collapse into bed, close their eyes, and if they’re lucky, remain that way for at least 7 hours a night. But some individuals break up the slumber into two shifts. 

Here enters the segmented sleep. It entails you go to sleep at night, then wake up after a few hours, and during the day go to bed for a couple of hours again. It works out for some people to sleep for 4 hours twice a day. 

Still, there are mixed perspectives on this sleeping activity. Even though there hasn’t been much research on whether sleeping shifts are healthy or not, you should avoid this routine unless there is a valid reason for you to do so. 

See also
The Best Sleep Tricks For People Who Struggle To Fall And Stay Asleep

Of course, if you naturally sleep that way and feel okay with it, then you can keep up with this procedure. Doing it on purpose and waking up in the middle of the night can impact your circadian rhythms – the internal clock that controls processes in your body (8).

If you tend to let yourself off the hook, raise the white flag when things get tougher than you expected, send yourself on an unconscious binge-eating trip – BetterMe app is here to help you leave all of these sabotaging habits in the past!

What Are The Phases Of Sleep?

The science of sleeping stages is engaging. Interestingly though, if you neglect one of the phases you’re more likely to feel like a squeezed lemon the next day. Check out the main 4 sleeping cycles you, hopefully, relive every night:

  • Stage 1 non-REM: This stage is the lightest as it takes around 1 to 5 minutes. Your breathing, heart rate, and brain waves begin to slow down, and your muscles relax.
  • Stage 2 non-REM: This stage lasts for 30 to 60 minutes. It occurs before the body enters deep sleep. Your muscles relax more and the temperature drops. 
  • Stage 3 non-REM: You are in the stage of deep sleep which lasts 20 to 40 minutes. Breathing and heart rate slow to their lowest levels.
  • REM (Rapid eye movement) sleep: During 90 minutes of falling asleep, you enter REM sleep. Your brain becomes more active, most dreaming occurs, and the arms and legs are temporarily paralyzed (3).

Your body needs to move through all these cycles several times per night. If you have a full sleep, you usually move around four to six times in all 4 cycles. But with only 4 hours of sleep you’ll get only one time to cycle through these stages twice. 

What Are The 6 Tips For Better Sleep?

Okay, you have all the knowledge about the optimal time sleep ranges and are ready for the changes. The good news, there are healthy and quite simple ways to not only promote better sleep but make your well-being more satisfactory for existence. In simple words, you look better, feel better, and perform better.

Check out the top 6 tips for better sleep and implement them today:

  1. Create a sleeping schedule for yourself. This means you turn in and wake up at the same time daily. Please note that weekends also count. People often neglect this rule on Saturdays or Sundays, excusing themselves with “Well, I can sleep longer, or deserve this all-night party”. Sufficient sleep is your door to a happier life, so don’t ruin it with regular guilty pleasures (6).
  2. Eat 2 hours before going to bed. You have little chance to fall asleep when you’re hungry. Make sure you don’t ingest nicotine or caffeine before turning in as it may interfere with your sleep. Choose something lighter, like a salad, and your body will thank you for that (6).
  3. Create a relaxing environment around yourself. Look at your room. Is there too much light? Then shut the curtains. Plus, cool the space down around you, especially during the dog days of summer when you can’t help sweating. Lastly, you already know this rule but limit the screen time on your phone, tablet, or any other device. You automatically feel sleepy if you spend some time in the dim room (6).
  4. Do something relaxing. Are you into podcasts or soothing jazz? While watching stories on social media is detrimental to your sleep, listening to your favorite song, meditating, or taking a bath should be chill for you. 
  5. Stay active every day. It’s amazing how your healthy diet and exercising altogether positively impact your sleep. No matter what you’re into swimming, jogging, strolling, or playing volleyball, staying active is vital for your sleep. Please avoid any physical exercises before bedtime (6).
  6. Resolve your worries. Usually, your lack of good sleep is the consequence of your nagging thoughts about something: your last fight with a relative, a big check for the renovation of your apartment, or a breakup with your beloved partner. If it’s a short-term issue you can wait but once it gets consistent talk to the specialist about it (6).
See also
Sleep Tricks: Silk Pillowcases

Doing these essential steps will aid you in faster and healthier sleep. 

What Are The Benefits Of Good Sleep?

Good sleep can be very impactful and enjoyable at the same time. You feel rested and get all the essential benefits of it. So, you change your habits, and diet, do physical activities, and solve your stressing issues. Finally, with good sleep you:

  • promote your memory and performance
  • lower the risk of gaining weight
  • regulate your calorie intake better
  • enhance athletic performance
  • lower the risk of heart diseases
  • recognize other’s emotions and expressions more qualitatively
  • may prevent depression
  • reduce inflammation in your body
  • get a stronger immune system (10).

You don’t neglect healthy sleep and end up with these benefits. Your life gets better when you feel perkier and invigorated to complete hard and easy tasks.

See also
Waking Up Tired And No Energy? Here's Why, And What You Can Do

is 4 hours of sleep enough


Is 4 Hours Of Sleep Enough For One Day?

The general rule says that adults need to sleep at least 7 hours per day. Therefore, sleeping 4 hours only is too little for the proper functioning of your body and brain. Sleeping for 4 hours on a regular basis can provoke a great number of health conditions, such as depression, fatigue, mood swings, stroke, weight gain, high blood pressure, and heart diseases. Thus, try to do your best to stick to healthier sleeping time ranges.

Can I Function On 3 Hours Of Sleep?

You can function on 3 hours of sleep but not at your best levels. If it’s a one-time thing then it won’t put you at any serious health risks but sleeping for 3 hours daily will negatively impact your well-being. Scientists claim that an average person needs 7 to 9 hours for proper functioning. 

Is It Better To Get 2 Hours Of Sleep Or Just Stay Up?

Both options are not appealing to your body but since you’re in the situation where you need to select one of them, getting 2 hours of sleep is better than no sleep at all. Why? The thing is, during sleep, your body replenishes hormones and repairs its tissues. Skipping the night’s sleep can impair your mental function and your mood may decline the next day.

Is It OK To Lose One Night Of Sleep?

It seems like one night of sleep loss isn’t a big deal. Nonetheless, it will disrupt your day-to-day physical, mental, and emotional well-being. The most common symptom of one night of sleep deprivation is raised levels of anxiety and mood swings. Thus, if you have a chance, sleep at least a little bit to partially avoid these problems.

The Bottom Line

Sleeping well is essential to the proper functioning of your body. It loads you with a great number of benefits, starting from the regulated weight to the prevention of serious health conditions. 

Is 4 hours of sleep enough? Here’s what science says. In this article, you’ve learned that the optimal sleeping time is 7 to 8 hours in adults. This means, 4 hours of sleep is not enough for your well-being. Sleeping for 4 hours is dismissive as it may provoke certain health conditions, such as depression, weight gain, fatigue, problems with memory and performance, heart diseases, high blood pressure, and a stroke. 

You need to keep tabs on your daily habits, including your dieting and physical activity to sleep better. Plus, creating a relaxing atmosphere without your devices will only raise your chances to slumber faster.



This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!


  1. How many hours of sleep are enough for good health? (2023,
  2. How Much Sleep Do We Really Need? (2023,
  3. Sleep calculator: How much sleep do you need? (2020,
  4. Sleep Deprivation (2023,
  5. Sleep effects on breathing and respiratory diseases (2009,
  6. Sleep tips: 6 steps to better sleep (2022,
  7. What Are Sleep Deprivation and Deficiency? (2022,
  8. What Is Segmented Sleep and Is It Healthy? (2022,
  9. What to know about sleep deprivation (2023,
  10. Why sleep is essential for health (2023,
Get started