A Simple Test for Sleep Deprivation

Do you know how sleep deprived you are? Although there are some tell-tale signs that point toward sleep deprivation, like feeling drowsy during the day, these signs may not always be present.

We can still be sleep deprived without feeling tired, or may not be able to recognise the symptoms that we’re experiencing. That’s where sleep latency and sleep latency tests come in.

About sleep latency

Sleep latency is the amount of time it takes for a person to fall asleep, and it’s a more concrete reflection of any sleep issues we might be facing.

In healthy adults, sleep latency tends to last between 10 and 20 minutes. Less than that, and you may be missing out on hours of sleep, or experiencing a poorer quality of sleep.

Clinically, sleep latency is often measured through the Multiple Sleep Latency Test. It is often carried out in a lab, but there’s also a simple test that can be carried out at home — the Sleep Onset Latency Test, also known as the spoon test.

It's possible to go through the day without noticing signs of sleep deprivation.

The spoon test

Ever drifted off in a class or webinar, only to be startled awake by your pen falling from your grasp? The spoon test works similarly, using a falling item to wake you immediately after you doze off.

What you'll need

  • A watch or clock
  • A metal spoon, or any item that makes a loud sound when it hits the ground, like a set of keys
  • A metal tray

How it works

  1. Make sure to carry out the test during the day, and try to skip your daily cup of coffee or tea.
  2. Place the metal tray by the side of your bed.
  3. Lie down, keeping one hand over the edge of the bed, directly above the metal tray. In this hand, hold the metal spoon.
  4. Take note of the time and close your eyes.
  5. As you fall asleep, your hand would let go the spoon, and the clatter of the spoon hitting the tray would wake you up. As soon as you awake, check the time again.

If you fall asleep under 15 minutes during the day, look into adjusting your sleep hours or quality. Image c/o @eleventhour.

What your results mean

The length of time from when you close your eyes to when you fall asleep is a measure of your sleep latency. In turn, your sleep latency can tell you how sleep deprived you are.

If you fell asleep in:

0-5 minutes: You are severely sleep deprived
5-15 minutes: You are a little sleep deprived
15-20 minutes: You are getting enough sleep

These only apply for sleep latency during the day. Over 20 minutes to fall asleep during the day is a good indicator that you’re well rested, but lying awake for over 20 minutes at night could reflect trouble falling asleep.

If you have a low sleep latency, try increasing your sleep hours, or adjusting your evening routine or sleep environment for better quality sleep.

If you have a high sleep latency but feel drained or exhausted during the day, you may be lacking in another area of rest (there are 7 in total!).

And finally, remember that your sleep latency at night can also be affected by other factors, like how much earlier or later it is compared to your usual sleep time, or if you’ve taken any medication, alcohol or caffeine in the evening.

You may also find these resources useful: