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Sleep Inertia: Everything You Need To Know

Fact Checked
Up to date
Update: June 29, 2023
5 min read

Written by

Manya Mishra
Content Writer

Medical reviewed by

Dr Dixit Thakur
Pulmonary and Sleep Specialist
Sleep Inertia

As soon as you wake up, you feel groggy, still floating between a thin line of sleep and wake. This heaviness is known as sleep inertia. During sleep inertia, you may feel slightly disoriented and tired. While it doesn’t last too long, some people tend to go through versions where it does. This article will tell you everything about sleep inertia. Read ahead for more!

What Is Sleep Inertia?

Sleep inertia is when you experience grogginess, fatigue, or cognitive impairment as soon as you wake up. It can last anywhere from 15 to 60 minutes. But some also experience sleep inertia for hours. As of now, we still don’t know the exact biological reason for sleep inertia. However, it is believed that sleep inertia is a sort of defence mechanism of the body to keep you in a state of sleep if you wake up unintendedly. 

If you experience prolonged or severe sleep inertia, there are chances that you will experience extreme confusion as soon as you wake up. Sleep inertia isn’t parasomnia but can lead to sleep drunkenness, which is one. However, if sleep inertia is causing any disruptions, it becomes essential to visit a doctor. 

Symptoms of Sleep Inertia

Sleep inertia symptoms are the same whether you wake from a nap or a good night’s sleep. Some of them are;

  • You feel highly groggy as soon as you wake up 
  • Unable to concentrate 
  • You may feel like going back to sleep

What Causes Sleep Inertia?

Scientists have been trying to understand more about sleep inertia and have come up with a few possible sleep inertia causes. They are;

High Sleep Debt

One of the main reasons why you may suffer from sleep inertia includes a high amount of sleep debt. It is the amount of sleep you owe your body for 14 days. Sleep debt occurs when you don’t give your body the sleep it deserves every night. Therefore, you can try sleeping for seven to nine hours every night to ensure you don’t suffer from chronic sleep inertia.

Slow-Wave Sleep (SWS)

Wondering why do I feel like crap in the morning, it can be because of disruptions in your slow-wave sleep (SWS). Slow-wave sleep, deep sleep, also known as non-REM sleep, is the period when your brain starts its healing and repair process. The cerebral blood volume goes down to introduce cerebrospinal fluid in the brain to flush out any memory-impairing toxins. But abrupt awakening during this period can hamper this procedure.

Recovery Sleep

Maybe the never-ending deadlines had you stretching the night, or possibly exams. It is known as recovery sleep when you stay up too late and then go to sleep. Paying up your sleep debt is a good idea. However, it is known to aggravate your recovery sleep.


Your chronotype,  your natural biological rhythm, affects your sleep-wake pattern. It can also influence how fast you can recover from sleep inertia. So, as per research, later chronotypes need more time to recover.  

Long Naps

While naps can be great to refresh you or pay your sleep debt, longer naps can increase sleep inertia. Therefore, it is essential to only extend your nap for up to 30 minutes. 

Core Body Temperature

As you fall asleep, the core body temperature dips down. Your body temperature is the lowest when you proceed to a deeper sleep cycle. So, waking up at this stage can make it challenging to fight sleep inertia.

How to Minimize the Effect of Sleep Inertia?

But don’t worry. There are sleep inertia cures that you can include in your everyday routine. 

Pay Down Sleep Debt

As aforementioned, high sleep debt at a stretch can aggravate sleep inertia. Therefore, while it is essential to cover up the missed sleep, keep it to a minimum. 

Play to Your Auditory Senses

Does your alarm tone make you happy or startle you? Well, as per new research, keeping your favourite tune as your alarm tune can reduce your sleep inertia. 

Indulge In Caffeine

Well, if you depend on caffeine to fight sleep inertia after nap or sleep, you are on the right path. Caffeine interferes with adenosine as it boosts your alertness. However, don’t overindulge in caffeine, as too much isn’t good for you. 

Bask in Sunlight

As soon as you wake up, open your blinds or go outside and bask in the sunlight. It not only helps you keep your circadian rhythm on track but also enables you to shake off any remaining traces of sleepiness. 

Nap Strategically

If you sleep less, taking short naps to fulfil any discrepancies is ideal. However, it is essential to be strategic and take at most 30 minutes of power naps. This is one of the tips on how to get rid of sleep inertia. 

Get Your Heart Pumping

How to stop sleep inertia? Morning exercise can be great for you to reduce your daytime drowsiness. Some of the advantages it fetches include;

  • It increases your core body temperature and wakefulness. 
  • Exercise releases hormones that promote wakefulness. 
  • It keeps your blood circulation at optimal levels and gives you a boost of energy.

Be Consistent

Finally, maintain a consistent sleep schedule. Sleep and wake up at the same time, as it keeps your sleep debt to a minimum and enables you to fall asleep and wake up easily. It keeps your circadian rhythm proper.

How is it diagnosed?

Sleep inertia is not a diagnosed medical condition but rather a transient state of impaired cognitive and motor performance that occurs immediately after waking up from sleep.

It is characterized by feelings of grogginess, disorientation, and reduced alertness. Diagnosis of sleep inertia is based on the subjective symptoms reported by individuals upon awakening.

Patients typically describe difficulties with concentration, memory, and coordination, as well as a strong desire to return to sleep. Objective assessments, such as cognitive tests and reaction time measurements, can also be used to evaluate the severity and duration of sleep inertia.

However, as there are no specific diagnostic criteria or standardized tests for sleep inertia, its assessment primarily relies on self-reported symptoms and the observation of impaired functioning upon awakening.

When to Talk to Your Doctor?

You must see a doctor if;

  • You have started experiencing extreme sleep inertia
  • You have long sleep inertia that disrupts your everyday life 
  • If you also have other sleep problems along with sleep inertia 
  • If you have started experiencing sleep inertia after medications 


If you experience sleep inertia for a few seconds to minutes, you are good to go, as it wears down quickly. However, it affects your day-to-day responsibilities if you have trouble shaking off the grogginess or drowsiness in the morning.


What is sleep inertia a symptom of?

Sleep inertia is a symptom of grogginess and disorientation that occurs immediately after waking up from deep sleep or a long period of sleep, often resulting in impaired cognitive and motor functioning.

Why is my sleep inertia so strong?

The strength of sleep inertia can vary based on factors such as sleep deprivation, awakening from deep sleep stages, disrupted sleep patterns, and individual differences in sleep quality and architecture.

Does exercise reduce sleep inertia?

Exercise can potentially help reduce sleep inertia by promoting better sleep quality and regulating the sleep-wake cycle, leading to a smoother transition from sleep to wakefulness. However, individual responses may vary.

Is it normal to have sleep inertia everyday?

Experiencing sleep inertia every day is not considered normal and may indicate underlying sleep problems or insufficient sleep duration. It is advisable to consult a healthcare professional for further evaluation and guidance.


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Written by

Manya Mishra
Content Writer
Bachelor's Degree in English Literature 7 years of experience as a content writer Has experience writing for various industries, including health and wellness, travel, and technology

Medical reviewed by

Dr Dixit Thakur
Pulmonary and Sleep Specialist
Pulmonary Critical Care & Sleep Specialist, vast experience of 10+ years in diagnosing and treating various sleep disorders.

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