What Is Sleep Inertia and Are You Suffering From It Without Knowing?

Sleep is one of the most important parts of our lives. After all, we spend up to a third of our lives asleep! If we’re not sleeping (or waking) well, we’re rarely able to function at our best.

If you often find yourself feeling a little off for a while after waking up - disoriented, drowsy, and a little slow - you’re showing symptoms of something called sleep inertia. It’s a common phenomenon, and one that can cause issues in your daily life. It can slow down your work & play and affect your decision making skills.

If this sounds familiar, then you may be suffering from sleep inertia! This article will explain a little about what sleep inertia is, what may cause it, and how you can take steps to remedy it. Read on to find out more!

What Is Sleep Inertia

What is sleep inertia, woman having a slow morning feeling drowsy

Sleep inertia is a feeling of being groggy or drowsy after waking up. It’s as if parts of your body and mind are still asleep. Essentially, they might as well be - you’re thinking and acting more slowly than usual. You’re awake, but not 100%. In fact, you’re in the state in between being asleep and awake, and it can last from anywhere between a few minutes to a few hours!

This can ruin your mornings, and even your whole day. If you’re slower in the morning, you might find yourself having to play catchup in the afternoon! It can make doing your job difficult - and in some cases dangerous. This means that it’s important to understand how sleep inertia works, and to take steps to prevent it.

Sleep inertia is actually quite common - just think how many people you know who have trouble waking up!


Sufferers of sleep inertia suffer a number of common symptoms. They’re often strongest right when you wake up. They’ll dissipate over time, but depending on the person, this can take anything between 5 minutes and a few hours. So, for some people, this is a very serious issue - 4 hours a day of feeling groggy and uncoordinated!

Feeling sleep inertia with being very tired and not able to focus on your day, woman not feeling good

On waking up, you’ll feel extremely groggy, and want to go back to sleep. You’ll feel mentally and physically slower for some time after waking up too. Paying attention to things can be difficult, as can simple things as remembering where things are. Generally speaking, you’ll likely feel pretty awful in the mornings - you’ll hate getting up, want to go back to bed, and find yourself unable to do things as quickly and easily as you normally can.


Sleep inertia still isn’t fully understood - we don’t know exactly what biological or neurological processes cause it. However, there are three common ideas as to how exactly sleep inertia can be explained.

The first idea is that sleep inertia is caused by an increase of delta waves in the sleeping brain. These happen during non-REM sleep, and and also can increase after a period of sleep deprivation. Delta waves be responsible for sleep inertia, the brain not having reduced them enough in time for waking up.

Higher levels of adenosine, a chemical in the brain, could also play a part in sleep inertia. Adenosine levels should normally be low upon waking up - but sleep deprivation might increase the levels of adenosine.

Finally, reduced blood flow to the brain could also be a factor. This could be similar to chronic fatigue syndrome.

Sleep inertia can be related to certain things in your lifestyle. If you’re having difficulty sleeping in general, then that’s likely to be a factor in your difficulty waking up. Poor sleeping habits in general can cause lots of issues! Stress, caffeine, and prescribed medications could all be considered as causes for sleep inertia.

Luckily there are a few things you can try to help out with sleep inertia if you’re suffering from it!


As the precise cause of sleep inertia isn’t known, it’s not easy to give a precise treatment. However, there are definitely things that you can try that can improve your sleep in general, and that may well help you reduce that awful drowsy feeling in the morning!

Getting the best sleep you can is always a good idea in general, so anything you can do to improve this will always be a good idea too! If you don’t have a good bedtime routine, try to improve yours. Try to go to bed at regular times, and do things to unwind and relax before bed too. Reading a book or listening to some relaxing music might help ease you into sleep better!

Caffeine could well be causing you problems sleeping! It’s generally a good idea to cut as much caffeine out of your diet as possible. You’ll likely improve your sleep a lot if you cut out caffeinated drinks before bed - and less during the day too! Cutting out alcohol before bed is a good idea too. Sure, a drink might make you feel sleepier, but alcohol can actually disrupt your REM sleep. And, of course, drinking to go to sleep is a terrible habit to get in to!

You could consider limiting your screen time before bed too. Too many of us try to fall asleep with a phone in our hand! Instead, put your phone, tablet, laptop, whatever away - and turn the TV off too. Keep them away from your bedroom if that helps!

Finally, don’t eat or drink anything too big just before bedtime. A light snack might help you sleep - you’ll likely find it difficult sleeping if you’re too hungry - but a huge meal is right out. Same with lots of drinks! You especially don’t want to have to get up multiple times during the night to visit the bathroom. That’s definitely going to disturb your sleep!

Lastly, if sleep inertia is becoming a serious problem for you, consider getting professional medical advice.


Sleep inertia is a common problem for many people, and it can be anything from an annoyance to a serious problem in peoples lives. Hopefully, this article will have taught you a little bit about sleep inertia, its symptoms, and some possible ways to alleviate it!