How to avoid sleep inertia

​Have you ever woken up and felt groggy and tired, like you’re still half asleep? Sometimes we write this feeling off as ‘not being a morning person’ but there is a medical term for this phenomenon, sleep inertia. Sleep inertia (SI) is extremely common and can be quite severe.

So, you’re probably wondering, how can I avoid sleep inertia? The good news is that there are steps you can take to feel better in the morning. Read this article before you go out and get a ‘don’t talk to me before coffee’ hoodie.

What is sleep inertia?

Sleep inertia is the ‘groggy’ or cloudy feeling some people experience just after waking up. It’s that fuzzy feeling you get when you haven’t fully woken up. Some people report feeling physically ill from the symptoms of sleep inertia. Sleep inertia is aptly nicknamed ‘sleep drunkenness’.

Sleep inertia occurs when you are physically awake, but your brain is still in a sleep state. Sleep scientists have found the brain works differently when experiencing sleep inertia. During sleep inertia, our brain produces slower brain waves and has less blood flowing to it compared to when we are fully awake.

Symptoms of sleep inertia

Everyone experiences sleep inertia differently, but common symptoms include:

• Grogginess
• Brain fog
• Dizziness
• Impaired memory and alertness
• Impaired ability to perform tasks or have difficulty holding a conversation
• Reduced reaction time
• Impaired or blurry vision
• Overwhelming desire to go back to sleep

The duration and severity of sleep inertia can vary. Sleep inertia often subsides within 1 to 30 minutes after waking. It can be more severe in chronically sleep-deprived people and night shift workers. The severity of sleep inertia can also vary depending on what stage of the sleep cycle you are in upon waking up. Waking up in the middle of a deeper stage of sleep can lead to more severe sleep inertia.

Causes of sleep inertia

There is still a lot to be discovered about sleep science and sleep inertia. Scientists know that the probability of sleep inertia is increased when waking up suddenly mid-sleep cycle.

From a physiological perspective, when you wake up, the brain stem – the part of your brain responsible for basic functioning – is immediately alert. However, our pre-frontal cortex (PFC) – which is in charge of our thinking and executive functions – needs some time to catch up and receive the correct amount of blood flow.

What can impact sleep inertia?

There are several things that can affect the severity of sleep inertia. One being the phase of the sleep cycle you are in when you wake up.

During a normal night’s sleep, humans go through 4 phases of sleep; stage 1 and 2, 3 and 4 (REM). Stages 1 and 2 are lighter stages of sleep. Stage 3 is the deepest and is referred to as ‘slow-wave sleep’. During this stage, our brain produces the slowest brain waves. If we are woken up mid-stage 3, your body takes the longest amount of time to ‘fully wake up’. Research shows stage 3 is the hardest stage to wake up from.

Napping can also cause sleep inertia. Because naps are so short, we tend to wake up mid-cycle. Our brain needs time to wake up from the nap.

How can sleep inertia affect your life?

As annoying and embarrassing sleep inertia can be, in most cases, it does not cause any long-term harm. Sleep inertia can affect anyone, including children and babies, particularly coming out of afternoon naps.

Sleep inertia can be an issue for night shift workers and people who perform complex tasks in their jobs (eg: Doctors, transport drivers). It can even increase your risk of a car accident if you are driving shortly after waking up.

Sleep inertia is very common. In most cases, it is normal. However, if you still experience sleep inertia for several hours after waking, despite getting a good night’s sleep, it may be worth speaking to a doctor.

How to avoid sleep inertia

There is no ‘magic pill’ to cure sleep inertia. However, there are some tricks that might be useful and help you avoid sleep inertia.

• Try your best to get a full night’s sleep. Being well-rested is key. Sleep deprivation can make sleep inertia worse and make it last longer.
• Don’t eat just before bed.
• Use a wake-up light or go to sleep with the curtains partially open (if you live in an area that is dark at night.) Waking up with natural light suppresses melatonin levels and you wake up feeling more refreshed.
• Try to go to bed and wake up about the same time every day to help regulate your circadian rhythm.
• Have a good morning routine. This sets cues and helps signal your brain to wake up.
• Wash your face. The burst of water can instantly wake you up.
• Exercise. Morning exercise is a great way to wake up and get ready for the day.
• Caffeine in moderation. We all know that a morning coffee can perk you up, just try not to overdo it. Excessive caffeine or drinking caffeine late in the day can cause sleep problems and thus exacerbate sleep inertia.
• Avoid having multiple alarms. Set your alarm for when you have to get up. Multiple alarms have been shown to not help relieve sleep inertia.
• Create a wind-down routine. Avoid caffeine and screen time in the evening and create a sleep-friendly bedroom.
• Drink water to rehydrate your brain. Don’t underestimate this last tip. During the night your body often gets dehydrated as it’s gone for so long without a drink. Rehydrating your body and brain in the morning will help you feel better throughout the day. If you don’t want plain water, try lemon water or herbal tea (no, coffee doesn’t count!)