What Is Sleep Latency and Why Is It Important?

A man lying in bed staring at his clock, unable to fall asleep.

Do you fall asleep as soon as your head hits the pillow? Or do you stay awake for a long time, tossing and turning?


How quickly you are able to doze off is called sleep latency, and it can be used to determine sleep quality. Let's learn more about it and see how you can improve it.

Key Takeaways

  • Sleep latency is the amount of time you need to fall asleep when you go to bed. Between 10 and 20 minutes is considered ideal.

  • If you fall asleep as soon as you go to bed, there is a high chance you are not getting enough quality sleep.

  • If you take a long time to doze off, you need to look at your lifestyle and figure out what is keeping you up. Anything from anxious thoughts to vigorous exercise before bed could be the culprit.

  • Good sleep hygiene can help you adjust your sleep latency and ensure you are getting quality rest.

Table of Contents

What Is Sleep Latency?

Sleep latency, also called sleep onset latency, is the amount of time it takes you to fall asleep once you are in bed.


If it takes you a long time to get to sleep, you may end up sleeping less efficiently. This means you won’t be spending enough time going through the different sleep cycles during the night.


Ironically, if you fall asleep as soon as you tuck yourself in, it may be a warning sign that you are not getting enough sleep.

What Is the Ideal Sleep Latency?

Ideally, adults will fall asleep 10 to 20 minutes after going to bed. A study published in Sleep Medicine found that the average mean sleep latency in healthy adults is 11.7 minutes.(1)


Children and teens may need as little as 5 to 10 minutes to drift off, and this will still be considered normal sleep latency. Those over 60 might need as much as 30 or more minutes to get to sleep.

Why Is Sleep Onset Latency Important?

A woman experiencing daytime sleepiness in the office due to poor sleep latency.

Sleep latency can be an indicator of sleep quality. It can also be used to diagnose sleep disorders and sleep deprivation.


A lack of sleep will impact both your mental and physical health. Not getting enough sleep will cause excessive daytime sleepiness and make you moody and cranky. It can also make you more accident-prone and significantly decrease your focus.


Over time, a sleep debt can increase your risk of developing conditions like heart disease and diabetes. It can also be a contributing factor to depression and anxiety.


If you notice any signs you are not sleeping deeply, or have trouble falling asleep, you might want to consider sleep latency testing.

What if Your Sleep Latency Is Too Long?

A long sleep latency means that you need more than 20 minutes to fall asleep every night.


When this is the case, you may end up missing out on REM sleep (also known as rapid eye movement sleep). This is when you dream and your brain processes information acquired during the day. Not getting enough REM sleep can impact your cognitive health. Without it, you won't feel rested enough either.


How long it takes you to reach REM sleep is called REM sleep latency. A study published in the National Library of Medicine says that it averages between 90 and 120 minutes.(2)


There are numerous factors that can cause bedtime sleeplessness. Taking more than 1 nap during the day can, for example, make it more difficult to fall asleep at night. Sleeping in a new bed for the first time can make it more difficult to get to sleep, too.


Stress and anxiety can make your mind buzz with unwanted thoughts, which can also make it difficult to fall asleep. A study published in Psychosomatic Medicine has found that rumination causes long sleep latency.(3)


Other potential culprits include:


  • Suffering from chronic or acute pain

  • Too much noise, light or heat in your bedroom

  • Leading a predominantly sedentary lifestyle

  • An irregular sleep schedule

  • Sleep disorders like insomnia or sleep apnea

What if Your Sleep Latency Is Too Short?

If you fall asleep as soon as you’re in bed, you probably have a lot of accumulated sleep debt. This means that you are consistently not getting enough sleep.


Drinking alcohol before bed can also lower your sleep latency. Certain conditions, like narcolepsy or idiopathic hypersomnia will do the same. If you suffer from either of these conditions, you will also experience excessive daytime sleepiness and disrupted sleep cycles.

How Is Sleep Latency Measured?

Several sleep tests can measure your sleep latency.

Polysomnogram

The polysomnogram is an overnight sleep study. It will most often be done at a sleep laboratory. It involves sleeping with sensors attached to your body that will keep track of your heart rate, breathing and brain waves.


This sleep test can determine how quickly you enter different sleep stages, and it can also diagnose sleep apnea.

Multiple Sleep Latency Test (MSLT)

The multiple sleep latency test (MSLT) measures how quickly you fall asleep for a daytime nap after a full night of sleep. You will be asked to take 5 naps, 1 every 2 hours. You will be woken up after napping for 20 minutes.


The multiple sleep latency test is also performed in a lab, with various sensors monitoring your sleep cycles.

Maintenance of Wakefulness Test

This test is only conducted if you have already been diagnosed with a sleep disorder and have begun treatment. It measures whether you can stay awake for certain periods of time.


Sensors will again be involved, and your task will be to stay awake in a dark room.


If you are considering a sleep study, make sure to prepare ahead and to consult your healthcare provider, who can recommend the best one for your specific needs.

How to Improve Sleep Latency

A man writing in his sleep diary to improve his sleep latency.

If you have discovered your sleep latency is less than ideal, here is what you can do to address the issue:


  • Try to find out what is at the root of it. Are you spending too much time scrolling on your phone in bed? Are you taking too many daytime naps? Do you suffer from a sleep disorder? Once you understand the cause, you can make changes that will help. Keeping a sleep diary can help you discover what is impacting your sleep.

  • Establish a calming night-time routine. Journal, read a book and listen to relaxing music. These activities will signal to your brain that it’s time to go to sleep.

  • Maintain a regular sleep schedule. Waking up and going to bed at the same time will help you avoid daytime sleepiness and nighttime sleep issues.

  • Don’t eat a heavy meal in the evening. Try to have a lighter dinner at least two hours before bedtime. Avoid eating sugary foods before bed.

  • If you can, avoid caffeine in the afternoon. Moderate your alcohol intake so that it doesn’t interfere with your sleep.

  • Get some exercise every day, but try not to exercise right before bed.

  • Make sure your bedroom provides an optimal, quiet environment for sleep. Invest in a mattress and pillow that match your sleep style. Remove any unnecessary electronics and light sources from the room. Use blackout curtains or wear a blackout sleep mask to help your mind and body slide into sleep.

  • If you are taking any medication, talk to your healthcare provider to make sure it does not adversely affect your rest.

  • If your sleep latency is too long or short and you can’t seem to get to the bottom of it, talk to your doctor.


Remember, while we all want to fall asleep fast and get a good night’s rest, snoozing off as soon as you hit the sack can be a sign of trouble.

Conclusion: What Is Your Sleep Latency?

Sleep latency refers to the amount of time it takes you to fall asleep when you get to bed. If you doze off in a matter of minutes, it probably means you are not getting enough sleep. If you spend more than 30 minutes tossing and turning, chances are you need to make some lifestyle adjustments.


Have you noticed your sleep latency has been off lately? How much time do you need to get to sleep? Let us know by commenting below!

Sources:  

(1) “Normal multiple sleep latency test values in adults: A systematic review and meta-analysis.” Sleep Medicine, pubmed.ncbi.nlm.nih.gov/37442016/. Accessed 7 May 2025.

(2) “Physiology, REM Sleep.” National Library of Medicine, www.ncbi.nlm.nih.gov/books/NBK531454/. Accessed 7 May 2025.

(3) “Rumination predicts longer sleep onset latency after an acute psychosocial stressor.” Psychosomatic Medicine, pubmed.ncbi.nlm.nih.gov/19622710/. Accessed 7 May 2025.


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