what actually happens if you don’t sleep enough?
“I never get enough sleep. I stay up late at night, cause I’m Night Guy. Night Guy wants to stay up late. ‘What about getting up after five hours sleep?’ ‘Oh that’s Morning Guy’s problem. That’s not my problem, I’m Night Guy. I stay up as late as I want.’ So you get up in the morning, you’re exhausted, groggy… ‘oooh I hate that Night Guy!’ See, Night Guy always [messes up] Morning Guy. There’s nothing Morning Guy can do. The only thing Morning Guy can do is try and oversleep often enough so that Day Guy loses his job and Night Guy has no money to go out anymore.”
– Jerry Seinfeld, Season 5: Glasses.
this bit lives rent free in my head. i replay this commentary at night when i want to watch just one more episode of stranger things and in the morning when i feel like shit because i watched just one more episode of stranger things. all while being well aware that I have a busy day lined up. but c’mon, it’s an hour, what’s the big deal? yes I’ll be groggy that day but i’m getting enough sleep on most nights this shouldn’t impact me that much, right?
sleeping ‘enough’ for healthy adults means getting 7-9 hours per night. your friend that tells you they only need 4 hours is lying to you, and themselves, and has just learned how to cope in a chronic state of sleep deprivation. kudos to them i guess. sleep deprivation is a term that means you’re getting less sleep than is needed to maintain daily wakefulness. wakefulness is a state of being alert and conscious, this is why there is a range for hours per night, some nights you need more to remain wakeful others less. the best way to figure out how much sleep you need is to play around with your time in bed. try 7 hours for a few days then slowly go up to 7.5, then 8 and so on. You can stop once you find a time that allows you to feel rested and not groggy mid day. you’re going to need some feel on this one just as a heads up, it’s not an exact science. for you, sleep deprivation would be getting less sleep than the hours you either just found out, or already know that you need.
if you sleep less than you need one night, like if you pull an all nighter, that would be termed acute sleep deprivation. some side effects from this type of sleep deprivation include excessive daytime sleepiness, depressed mood, poor focus, impaired memory and executive function (the brains management system that helps with planning, focus, memory, self-control, and organization to achieve goals). further, if you have a medical condition like obesity, hypertension, depression, and/or anxiety, this type of acute sleep deprivation can exacerbate these. but all nighters happen on rare occasions, missing an hour or so shouldn’t result in any negative consequences, right?
wrong. consistently getting less sleep than you need is termed chronic sleep deprivation and can be more detrimental to your health than occasionally pulling an all nighter. chronic sleep deprivation produces the same physiological markers you see with many comorbid conditions including elevated cortisol and inflammatory markers as well as a decrease in testosterone levels.
elevated serum cortisol levels have correlations with depression, anxiety, hypertension, obesity, and type II diabetes. chronically elevated inflammation levels can result in obesity, diabetes & impaired glucose tolerance, cardiovascular disease and hypertension, anxiety and depressive symptoms, stroke, increased alcohol use, and lower reported markers of quality of life. testosterone enhances the function of gamma-aminobutyric acid (GABA) and serotonin systems in the brain. this reduced function provides a possible link between depression and anxiety. getting less sleep than you need (even by an hour) can be considered a major risk factor for the onset of chronic disease, poor health choices and lower overall quality of life.
now, there are things you can do to help make sure you get the recommended sleep you need consistently. the first and easiest thing is to check your sleep hygiene, this means turning netflix off at least 30 minutes before going to bed, dim your lights and make your room as dark as possible and set a calming screen-free nightly routine. this should help the majority of people, you just need to be disciplined in order to follow and not binge watch shows late into the evening. but for others who have trouble falling and staying asleep here are some do’s and don’ts you can follow:
falling asleep
do:
avoid caffeine or nicotine close to bedtime
go to sleep and wake up around the same time each day (weekends too) [7]
watch the sun set, or look at the sun low in the sky to transition your body to “night-time”, then keep lights off, dim, or warm from this point on
take a hot shower or sauna before bed, after this heat your body will work to cool itself off which will encourage sleep onset
avoid screens within 60-90 minutes before bed, these lights can trick your brain to thinking it’s daytime disrupting your circadian rhythm
don’t:
exercise close to bedtime, exercise releases cortisol which is an arousal hormone that works in opposition to falling asleep
ice bath, your body will work hard to re-warm itself post which is in opposition to what your body needs to fall asleep (it needs a drop in temperature not rise)
turn to pharmaceuticals without talking to your doctor, and before assessing your sleep hygiene
staying asleep
avoid alcohol close to bedtime, although alcohol can make it easier to fall asleep, it can cause you to have a sleep that tends to be lighter than normal. This makes it more likely that you will wake up during the night
avoid meals before bedtime (2-4hrs), digestion will prevent deeper restful sleep and can result in frequent wake ups during the night
limit how much fluid you drink before bed, good rule of thumb is to get your daily water intake in by 3p then only sip after this
miles is a trainer, speaker, writer, and consultant who specializes in performance and longevity within the health and wellness space. with over ten years of experience, a masters degree in exercise and nutrition science and multiple strength and conditioning certifications miles aims to combine practical application with research to provide actionable strategies for people looking to live longer and excel athletically.
references
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https://www.nhlbi.nih.gov/health/sleep/stages-of-sleep
Patel AK, Reddy V, Shumway KR, et al. Physiology, Sleep Stages. [Updated 2024 Jan 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526132/
Antony JW, Schönauer M, Staresina BP, Cairney SA. Sleep Spindles and Memory Reprocessing. Trends Neurosci. 2019 Jan;42(1):1-3. doi: 10.1016/j.tins.2018.09.012. Epub 2018 Oct 16. PMID: 30340875.
Hilditch CJ, McHill AW. Sleep inertia: current insights. Nat Sci Sleep. 2019 Aug 22;11:155-165. doi: 10.2147/NSS.S188911. PMID: 31692489; PMCID: PMC6710480.
Hanson JA, Huecker MR. Sleep Deprivation. [Updated 2023 Jun 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK547676/#
https://www.nhlbi.nih.gov/health/sleep-disorder-treatments#:~:text=Avoid%20caffeine%2C%20nicotine%2C%20and%20alcohol,bright%20light%20similar%20to%20sunlight.
