Sleep Inertia: What It Is and How To Get Rid of It

Pop quiz time! What is Isaac Newton’s first law of motion?

Answer: An object at rest tends to stay at rest and an object in motion tends to stay in motion.

This principle is called inertia. It’s why we lurch forward when we slam on the brakes and long jumpers race down a runway instead of standing still at the takeoff board. We also use the word “inertia” to describe resistance or refusal to change — to transition to something new.

Well, our brains can experience inertia, too. In fact, inertia is probably one of the first experiences you have each day. Sleep disorders specialist Michelle Drerup, PsyD​, explains.

What is sleep inertia?

Sleep inertia is the transitional state you experience when you aren’t asleep … but definitely aren’t awake yet either. Your body’s been at rest. And it’s fighting to stay that way.

Common symptoms of sleep inertia include:

• Drowsiness and disorientation.
• Inattentiveness and poor reaction time.
• Decreased motor skills, which can cause balance and coordination problems.
• Difficulty communicating, reasoning, remembering and learning.
• Poor decision-making skills and/or risky behavior.
• Mood swings and irritability.

Here’s an experience you’ve probably had: You wake up to your alarm, only to discover you’ve hit snooze five times already. Now, you’re running late! You don’t remember deciding to sleep in, much less traveling to your dresser to snooze your alarm, but it happened. That, gentle reader, is a classic example of sleep inertia.

“It’s common to experience cognitive issues, like mental fogginess,” Dr. Drerup explains. “But sometimes, it’s more of a physical phenomenon — a feeling of malaise or lethargy.” Sleep inertia usually lasts anywhere from 15 to 60 minutes. If you’re badly sleep-deprived, that feeling could last even longer: That’s called sleep drunkenness.

It’s not a health concern in and of itself, but sleep inertia can be very dangerous because it can make us more accident-prone. That danger ramps up if you’re doing high-risk activities like driving, operating heavy machinery or performing surgery.

What causes sleep inertia?

Sleep inertia isn’t a pleasant feeling, and in certain circumstances, it can pose a threat to your health and safety. But it’s not a health problem. It’s a natural phenomenon we all experience from time to time.

“I think there’s a misconception that people wake up and are ready to jump out of bed full of energy,” Dr. Drerup notes. “But that’s not the norm for the majority of us.”

So, it’s a common occurrence. But why does it happen?

According to Dr. Drerup, sleep inertia typically happens when you wake up abruptly from a deep sleep. There are four different sleep stages, which fall into two different categories: non-REM (NREM) sleep and rapid eye movement (REM) sleep. We cycle through all four stages over the course of 90 to 120 minutes:

1. NREM stage 1 is the first and shortest stage — the one you enter upon first falling asleep. Your body isn’t fully relaxed yet, so this is the stage in the cycle when you experience the lightest sleep. It’s pretty easy to wake somebody up during NREM stage 1 sleep, but if left alone, you’ll transition into NREM stage 2 within about seven to 10 minutes.
2. NREM stage 2 is associated with a drop in body temperature, relaxed muscles and slowed breathing and heart rate. Your overall brain activity slows, but there are short bursts of activity called K complexes that help you sleep through noises and other potential interruptions. Throughout a night of sleep, you typically spend about half of your time in NREM stage 2. It’s harder to wake up during NREM stage 2 than it is during NREM stage 1.
3. NREM stage 3 is the deepest stage of sleep. During this phase, your core body temperature drops to its lowest point and your brain produces delta waves (which is why experts also call NREM stage 3 “slow wave sleep”). You’re most likely to experience sleep inertia if you wake up during NREM stage 3.
4. REM sleep is the final stage of sleep in each sleep cycle and you spend progressively more time in this stage of sleep the longer you slumber. Your body temperature begins to rise, your brainwaves speed up, your muscles paralyze and the majority of your dreams occur in REM sleep. During REM sleep, your brain activity actually looks more similar to your brain activity when you’re awake.

Common causes (or contributing factors) of sleep inertia include:

• Waking out of NREM stage 3 or deep sleep.
• Insufficient sleep time or not getting an adequate amount of sleep, which Dr. Drerup says can cause or worsen episodes of sleep inertia.
• Medications or substances that disrupt your sleep patterns, like antihistamines, benzodiazepines, alcohol, opioids and beta-blockers.
• Health conditions like major depressive disorder, bipolar disorder, obstructive sleep apnea, delayed sleep phase syndrome and idiopathic hypersomnia.
• Working a night shift, which can cause shift work sleep disorder (SWSD).

How to get rid of sleep inertia

Nobody necessarily wants to wake up groggy, but it can be helpful in certain situations.

“There are theories out there that sleep inertia is potentially protective,” Dr. Drerup shares. “You’re going to awaken during the night, to go to the bathroom, for example. Being able to stay in a state of semi-alertness in those moments can help you drift back off to sleep quickly.”

Again, while sleep inertia isn’t a problem, it can become problematic when you don’t have the opportunity to finish resting. Instead of trying to solve or cure sleep inertia, Dr. Drerup says that our goal should be to reduce its frequency and minimize its impact on our daily lives.

You can start with RISE-UP.

The RISE-UP method

RISE-UP is an acronym that sleep experts developed in 2018. It was part of an experiment aimed at helping people with bipolar disorder and insomnia reduce the intensity and frequency of their sleep inertia. But according to Dr. Drerup, anyone can benefit from the RISE-UP method.

Here’s how the acronym breaks down:

• Resist the urge to hit the snooze button. Oversleeping isn’t the answer. If you wake up, fall back asleep and wake up again, your sleep-wake cycle might get thrown off. If you tend to hit snooze without realizing it, try moving your alarm to the other side of the room so it takes more effort to turn it off.
• Increase your activity for the first hour. Whether you take your dog outside first thing for a morning walk or do some sun salutations as soon as you get up, fitting some movement into your morning will get your blood pumping and help you wake up.
• Shower. Showers and baths are wonderful. Taking one at night can help promote relaxation and sleep. And morning showers are a terrific way to wake your body up! If you’re feeling brave, try taking a cool or cold shower — the sudden temperature change will kick your sympathetic nervous system into gear, increase your dopamine levels and improve your blood circulation. If you don’t like showering in the morning, splashing cold water on your face is a great substitute.
• Expose yourself to sunlight. Electricity may be one of the miracles of the modern world, but as far as our bodies are concerned, there’s no light quite like sunlight. So, have your morning coffee on the porch or sitting in front of a big window. Running late? Even sitting in the car for a few minutes before starting your commute can help!
• Upbeat music. The Bee Gees, Beyoncé, BTS, Busta Rhymes: They’re all natural enemies of sleep inertia. Make a playlist of happy, danceable songs that are guaranteed to get you energized in the morning. Don’t have time to cut a rug? That’s OK! Consider getting a portable shower speaker. That’ll take your shower singing to the next level!
• Phone a friend. Alarm clocks and wake-up calls can be ear-splitting. But they can also be easy to ignore — after all, your devices don’t get mad when you turn them off or expect you to behave like a member of polite society. Interacting with other humans is a natural way to improve awareness and attention. Whether you bike to work with your neighbor, shoot the breeze with your barista, call your parents or chat with an anti-inertia “accountability buddy,” you’re likely to perk up a bit.

Other tips for reducing sleep inertia

The RISE-UP method is helpful, but Dr. Drerup says there are plenty of other tips for minimizing sleep inertia that are worth keeping in mind, too.

• Improve your sleep hygiene. You’re less likely to struggle with sleep inertia if you’re well-rested. And good sleep hygiene improves your odds of that actually happening.
• Adjust your sleep schedule. Be really honest with yourself: How much sleep do you need a night — and how much are you actually getting? If sleep inertia is an issue for you, you may need to increase your sleep budget. Dr. Drerup recommends going to bed 30 minutes earlier for a while to see if that helps. You can also try integrating naps into your life. Just make sure you keep them short and sweet. Power naps are a great way to rest while avoiding sleep inertia.
• Use caffeine strategically. You don’t need coffee or tea to get over sleep inertia, but they don’t hurt! And both coffee and tea can be good for you if you skip the milk and sugar. Just be sure not to overdo it. Over-caffeination can cause unpleasant side effects and may make it harder to fall asleep at night. Which could mean dealing with sleep inertia the next morning.
• Stay hydrated. You don’t want to guzzle 40 ounces of water before bedtime, but make sure you drink plenty of water throughout the day. When we’re well-hydrated, we get better quality sleep and are less likely to experience sleep inertia, dry mouth or headaches when we get up.
• Make mornings routine. As soon as you wake up, Dr. Drerup suggests changing out of your pajamas and making your bed. These and other morning habits can help you perk up (and make getting back in bed harder to justify).
• Try a light-emitting alarm. Dr. Drerup notes that you’re less likely to get sleep inertia when you wake up gradually with nature’s alarm clock: The sun. Sunrise alarm clocks mimic that experience by slowly lighting up over the course of anywhere from 15 to 60 minutes. If you’re still snoring when the sunrise simulation ends, an alarm will sound. (Side note: Many of these clocks also have a sunset function, which may help you fall asleep faster at night!)

When is it something more serious?

While sleep inertia isn’t technically a medical problem, it can negatively impact your safety and quality of life. So, when is it time to see a healthcare provider about it?

Dr. Drerup recommends making an appointment with a sleep specialist if you’re finding that the feeling of sleep inertia is lingering throughout the day and interfering with your ability to function. It’s also worth the trip if you struggle with extended periods of sleep inertia, regardless of the amount or quality of sleep you’re getting.

“If you’ve made a consistent effort to implement changes like RISE-UP and it doesn't seem to be helping — or it’s making things worse — it’s time to see your provider.” Dr. Drerup recommends. “They need to figure out if an untreated health condition is causing or worsening your sleep inertia.”

Whatever your circumstances, sleep inertia is never going to disappear completely. It’s a natural phenomenon. But that doesn’t mean you have to take it lying down.

“We just have to find strategies to manage it better,” Dr. Drerup encourages. Just be sure to prioritize your sleep, your safety and the safety of others as you adjust your sleep hygiene.