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Sleep Expert On How to Know if You Have Short Sleep Syndrome

Short sleep syndrome is when you biologically only need about four to six hours of sleep. Use the RISE app to find out how much sleep you need.
Updated
2024-02-17
11 MINS
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Chester Wu, MD, Rise Science Medical Reviewer
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We bring sleep research out of the lab and into your life. Every post begins with peer-reviewed studies — not third-party sources — to make sure we only share advice that can be defended to a room full of sleep scientists.
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Updated Regularly
We regularly update our articles to explain the latest research and shifts in scientific consensus in a simple and actionable way.

Short Sleep Syndrome: What You Need to Know

  • Short sleep syndrome is when you biologically only need about four to six hours of sleep.
  • It’s not a medical term, so there isn’t an agreed-upon set of symptoms. Individuals with short sleep syndrome feel energetic, focused, and refreshed without caffeine or environmental stimulation, and there are no negative health impacts from getting this little sleep if you have short sleep syndrome.
  • It’s extremely rare, and most of us need closer to eight hours of sleep, even if we feel fine on less sleep.
  • The RISE app uses sleep science algorithms and your individual phone use data to work out how much sleep you need.  

Short sleep syndrome is when you only need a few hours of sleep. It sounds like a dream, but before you get your hopes up, it’s extremely rare. 

And even if you feel fine after a short night of sleep, it’s very likely you don’t have short sleep syndrome. 

Read on to learn more about this syndrome and how you can use the RISE app to find out how much sleep you need exactly.

Ask a Sleep Doctor

Ask a Sleep Doctor

We asked Rise Science sleep advisor and medical reviewer, Dr. Chester Wu, who is double board certified in psychiatry and sleep medicine, for his thoughts on short sleep syndrome.

“It’s true that some lucky people genetically need less sleep than the average person, but those people are few and far between. If you’re sleeping for a short amount of time, you’re very likely sleep deprived and putting yourself at risk of health issues like weight gain, depression, and cardiovascular disease.”

What is Short Sleep Syndrome? 

Short sleep syndrome is when you genetically need much less sleep than the average person and your energy, health, and performance aren’t impacted by the little sleep you get. 

It’s also known as short sleeper syndrome or SSS. It’s not a medical term, so there’s no set definition for it, but it’s generally used to describe those who only need about four to six hours of sleep.

SSS can also be described as “natural short sleep,” and it’s very different from habitual short sleep or insufficient sleep syndrome, when you get too little sleep due to sleep disorders, stress, or staying up late on purpose, for example. 

SSS is extremely rare. Estimates vary, but about 1% of the population could be natural short sleepers.

It’s thought short sleep syndrome is caused by a gene mutation. Most research on the topic is by Ying-Hui Fu and Louis Ptáček out of University of California, San Francisco.

But don’t hold your breath. In his book, Why We Sleep, Matthew Walker says, “It is far, far more likely that you will be struck by lightning (the lifetime odds being 1 in 12,000) than being truly capable of surviving on insufficient sleep thanks to a rare gene.” 

And, unfortunately, you can’t just become a natural short sleeper. As one 2021 paper on the topic describes it, “This sleeping habit is not meant to be practiced or learned upon one's desire, but rather is an intrinsic nature that lasts lifelong.” 

Heads-up: We looked at how much sleep 1.95 million RISE users aged 24 and up need. It ranged from five hours to 11 hours 30 minutes. While some people do only need a measly five hours of sleep, you can see how rare it is. The median is eight hours and 48% of users need eight hours or more. 

The RISE app can tell you how much sleep you need.
How much sleep RISE users need.

What Are the Symptoms of Short Sleep Syndrome? 

Short sleep syndrome isn’t medically recognized, so there isn’t an agreed-upon set of symptoms. 

The symptoms of short sleep syndrome can include: 

  • Only sleeping for about four to six hours  
  • Feeling energetic, focused, and refreshed without caffeine or environmental stimulation 
  • Not increasing your sleep time on your days off or with naps  
  • Always having had these sleep patterns (SSS is a lifelong trait) 

Interestingly, the average nap length among RISE users is one hour 40 minutes! If you have a short sleep duration at night, but take long daytime naps, you’re probably not a natural short sleeper. 

What Causes Short Sleep Syndrome? 

Short sleep syndrome may be caused by a gene mutation. Research from 2009 on natural short sleepers found the DEC2 mutation can cause shortened sleep duration. 

Since then, more rare mutations have been found.

A 2021 systematic review states that SSS can be caused by mutations in these genes: 

  • DEC2
  • NPSR1
  • mGluR1
  • β1-AR

The short sleep effects can even be replicated. A 2019 study found when mice were genetically engineered to have the ADRB1 mutation they slept 55 minutes less. Humans with the mutation sleep two hours less compared to those without it. 

As it’s genetic, SSS may be hereditary. But these genes are non-obligatory, meaning they need to be expressed to produce the trait of short sleep. In non-science speak, having a short sleep gene doesn’t guarantee you’ll be able to get by on fewer hours of sleep. 

And as we’ve said, it’s incredibly rare. The NPSR1 gene, for example, is found in fewer than one in 4 million people!

There’s not much research on SSS as it’s so rare and hard to study. More studies are needed to determine what exactly causes it.

How Do I Know if I Have Short Sleep Syndrome?

It can be hard to know if you have short sleep syndrome. You may sleep for six hours or less a night and feel fine during the day, but that doesn’t mean you’re actually fine. 

Your body produces more of the alertness-boosting hormones cortisol and adrenaline to help you function on no sleep and your brain’s reward system is fired up, so you feel more positive. These are two reasons you subjectively feel more energized on less sleep

Sleep research shows we may not notice our mental performance getting worse after sleep loss, and one study found people who thought they were well-rested got more than three hours of extra sleep when they got the chance.

A 2018 study found habitual short sleepers (defined in this study six hours of sleep or less) were more mentally impulsive — even if they felt fine on little sleep — compared to medium-length sleepers (defined as seven to nine hours of sleep). 

And a 2021 sleep study found how people feel about their sleep has more of an impact on fatigue than sleep duration. 

How you feel about your sleep can also impact performance. One study found participants performed better on a task when they were told they’d had good quality sleep the night before. And another group performed worse when they were told they’d had poor quality sleep. So you might be performing better, just because you think you’re sleeping fine.  

Plus a strong cup of coffee or other stimulants may mask daytime sleepiness. A 2016 paper states habitual short sleepers who believe they function fine may need environmental stimulation to stay awake and may not even realize how sleepy they are.

Dr. Jamie Zeitzer, co-director of the Center for Sleep and Circadian Sciences at Stanford University and one of our sleep advisors, agrees. 

“There are many people who get less than six hours but actually need more — most just caffeinate the main symptom (sleepiness) away and don't realize that they are damaging their health and trading less sleep for less effective wake.”

Finally, you may attribute symptoms of a lack of sleep — like digestive issues or acne — to other things, like diet or stress. 

All this is to say that it’s hard to know if you're really doing fine on little sleep. The only way to know is to find out how much sleep you need.

We’ve covered more on how to know if you’re getting enough sleep here.

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How to Find Out How Much Sleep You Need?  

Everyone needs a unique amount of sleep. Don’t just aim for the generic seven to nine hours and hope for the best. 

Guidelines, such as those from the National Sleep Foundation, are based on self-reported data, which can be inaccurate, and on how much sleep people get, not what they actually need. Plus, seven to nine hours of sleep is a huge window! 

Use RISE to find out exactly how much sleep you need.

RISE uses proprietary sleep-science-based models and a year’s worth of your phone use behavior to work out your sleep need. You’ll get a number in hours and minutes, so you can see whether you naturally need a short amount of sleep or not. 

You can also work out how much sleep you need manually by waking up without an alarm for a week or two and keeping a sleep diary. 

This method can be tricky to get right, however, as it’s hard to tell when exactly you fall asleep and whether you’re sleeping more because you need more sleep or because you’re recovering from recent sleep deprivation. 

You may also temporarily need more sleep when recovering from:

  • Illness
  • Injury
  • Intense exercise  

We’ve covered more on how much sleep you need here.

Is Short Sleep Syndrome Bad? 

True short sleep syndrome isn’t bad. Those with short sleep syndrome don’t experience any negative impacts from sleeping for a short amount of time as that’s what their body needs. 

Experts believe SSS may come with some benefits. Other than getting extra hours in the day, those with SSS may be more optimistic and energetic, better at multitasking, have a higher pain threshold, avoid jet lag, and even live longer. 

Hint: If you’re feeling irritable, low, and struggling to concentrate on even a single task, you’re probably not a natural short sleeper and need more sleep.

Most of us don’t have short sleep syndrome and are simply habitual short sleepers. In this case, we’re sleep deprived — and that is bad. 

Health Implications of Not Getting Enough Sleep 

In the short term, habitual short sleep can lead to: 

In the long term, habitual short sleep can lead to: 

  • High blood pressure
  • Diabetes 
  • Weight gain and obesity 
  • Cardiovascular disease 
  • Anxiety
  • Depression 
  • Long COVID (a 2023 study found habitual short sleep in those with pre-existing conditions increased the risk of long COVID) 
  • Serious health problems (a 2023 study found shorter sleep duration was linked to higher odds of having several health issues)
  • Early death  

How to Treat Short Sleep Syndrome? 

Short sleep syndrome doesn’t require any treatment. If you genetically need five hours of sleep, for example, and you get five hours of sleep, there’s nothing to fix. 

As we’ve shared, though, most of us don’t have short sleep syndrome and in fact need much more sleep than we’re getting. Read on to find out how to treat that.

How to Get More Sleep?

To get more sleep, focus on improving your sleep hygiene. This is the name for the daily habits that can help you fall and stay asleep. 

Good sleep hygiene includes: 

  • Getting out in sunlight for at least 10 minutes each morning (make it 15 if it’s overcast of you’re sitting behind a window) 
  • Keeping a regular sleep schedule, even on weekends 
  • Avoiding caffeine, intense exercise, alcohol, and large meals close to bedtime 
  • Making sure your bedroom is cool, dark, and quiet 

To nail your sleep hygiene, follow RISE’s personalized recommendations. The app tells you when to do 20+ good sleep behaviors at the right time for your circadian rhythm, or body clock. 

These habits sound small, but RISE users say they make a big difference. 

“After using this for a few months I started noticing all the small things that significantly impact my sleep. Just becoming more aware of when’s the best time to drink caffeine, eat dinner, and get sunlight according to my circadian rhythm has helped my sleep quality tremendously.” Read the review

RISE app screenshot showing sleep hygiene habit reminders
The RISE app guides you through 20+ sleep hygiene habits.

RISE users on iOS 1.202 and above can set up their 20+ in-app habit notifications here

Heads-up: Speak to a healthcare provider if you think a sleep disorder like insomnia or sleep apnea is causing you to sleep for a short amount of time. 

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How to Catch Up on Sleep? 

Just realized you’re a habitual short sleeper and don’t have the magic genes? Don’t fret, you can catch up on lost sleep.

Here’s how: 

  • Head to bed a little earlier 
  • Sleep in a little later 
  • Take short afternoon naps 
  • Improve your sleep hygiene (to spend more time asleep in bed)

RISE can work out how much sleep debt you have and keep track as you pay it back. Sleep debt is the amount of sleep you owe your body.

You may think you feel fine on little sleep, but you’ll feel even better when you pay back sleep debt.

“Before seeing the sleep debt numbers I didn’t understand how exhausted I really was. The biggest difference was when I finally reduced it to 0. It was a journey of several months, but I felt years younger after.” Read the review.

Learn how long it takes to recover from sleep deprivation here and more on how to do it.

RISE app screenshot showing how much sleep debt you have
The RISE app works out how much sleep debt you have.

RISE users on iOS 1.202 and above can view their sleep debt here.

Find Out How Much Sleep You Really Need 

People with short sleep syndrome thrive on little sleep — but most of us don’t have it. 

Use RISE to find out your genetically determined sleep need to know if you naturally need little sleep. Keep an eye on your sleep debt to make sure you’re getting enough shut-eye.

And if you struggle to meet your sleep need, follow RISE’s 20+ sleep hygiene habit reminders to fall and stay asleep more easily. The app helps 80% of users get more sleep within five days!

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RISE makes it easy to improve your sleep and daily energy to reach your potential

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