You probably know the feeling all too well — grogginess that seems to weigh you down when you wake from sleep.

That heavy feeling right after you wake up is called sleep inertia. You feel tired, maybe a little disoriented, and not quite fully ready to hit the ground running. It can affect anyone.

It usually doesn’t last that long, but some people experience a version that lasts longer, known as prolonged sleep inertia.

In some cases, people who experience severe morning sleep inertia may be at higher risk for confusional arousal, or sleep drunkenness, a type of parasomnia.

Parasomnias are a group of sleep disorders that involve unwanted events or experiences that occur while you’re falling asleep, sleeping, or waking up.

Sleep inertia isn’t considered a parasomnia, however, it can warrant a visit to a sleep specialist if it causes too much disruption in your life.

When you’re yawning and stretching and trying to come to life after waking up, you may not be wondering why you feel so groggy. But scientists have been investigating possible neurophysiological causes of sleep inertia, and they’ve proposed a few possible ideas:

  • Higher levels of delta waves: These are electrical waves in the brain associated with deep sleep. Scientists can measure electrical activity in the brain with an electroencephalogram (EEG). They’ve found not only higher levels of delta waves in people with sleep inertia, but fewer beta waves, which are associated with wakefulness.
  • Slower brain reactivation: Research has also shown that there may be a slower reactivation of certain parts of the brain after waking, including the prefrontal cortex regions that are responsible for executive function.
  • Slow blood flow in the brain: There also might be a lag in the time it takes for cerebral blood flow velocity to speed up after waking.

Whether you’re waking up from a nap or waking up from a night of sleep, the symptoms of sleep inertia are pretty much the same.

You feel drowsy and groggy. You might also have problems concentrating on information or making connections. Or, you might wave other people off while you rub your eyes or make yourself a cup of coffee.

Now, the good news. Typically, sleep inertia disappears after about 30 minutes, according to a 2019 analysis.

In fact, it can sometimes disappear within 15 minutes. However, what some scientists call a “full recovery” takes about an hour to achieve — and it can continue to improve over the course of about 2 hours.

Severe morning sleep inertia, which affects both adults and adolescents, can last for a long time and disrupt your ability to get to work or school on time. That’s when you might want to see a doctor, especially one with expertise in sleep disorders.

A sleep study can provide more insight into your sleep patterns and contributing factors.

Your doctor may also ask you about possible factors that can contribute to sleep arousal, such as:

  • stress
  • other sleep disorders
  • depressive disorders
  • medications you’re taking
  • night shift or rotating shift work that could have a detrimental effect on your sleep

If your doctor diagnoses you with severe morning sleep inertia and it’s causing you distress or disrupting your life, you may need to undergo some kind of treatment.

However, your doctor’s recommendations may vary based on whether you have any other types of sleep disorders, such as sleep apnea.

Your overall health and lifestyle may also play into treatment recommendations. For instance, you may need to reduce or eliminate alcohol use.

However, if you’re experiencing garden-variety grogginess after waking up, you might just try a few countermeasures to overcome the fogginess.

For most people, sleep inertia might not be problematic enough to see a doctor. But you still have to grapple with the effects when you’re awake.

A few strategies may help:


You’ve probably already thought of this. If you’ve ever blearily reached for a cup of coffee upon waking, you may be on the right track.

Caffeine can help you shake off some of the effects of sleep inertia.

However, you do have to be careful. Researchers suggest that consuming caffeine can be more useful at certain times than others, because it can disrupt your ability to sleep during your regular sleep time.

You could consider popping in a stick of caffeinated gum. A 2013 study found that caffeinated gum was effective in improving response speed and alleviating some of the effects of sleep inertia. However, the study was small, with only 15 participants, and some suggest that gum might not work quickly enough for urgent situations.

Strategic napping

A nap may be just the ticket to help you avoid sleep inertia. But the timing of the nap is very important, according to a 2017 analysis of short-duration naps.

A short nap, ideally between 10 to 20 minutes in the afternoon, can help counteract your sleepiness.

Researchers caution that this kind of short nap is really only effective if you’re not already sleep deprived. And if you do shift work, you may need to also consider the time of day and your prior sleep situation.

Light exposure

A 2016 review of studies suggests that getting a glimpse of the sunrise might help you speed up the process of feeling fully alert after waking.

Exposure to dawn light — even artificial dawn light with a light box — may help you feel more alert and better prepared to perform certain tasks.

It might be worth a try, but more research is necessary.

Sleep schedule rearrangement

Consider when you’re trying to sleep. According to a 2017 study, your body’s circadian rhythms have an influence on sleep inertia.

Your body wants to sleep during the “biological night,” the time when your body’s circadian rhythm promotes sleep. You’re going to have more trouble performing cognitive tasks right after you wake up, if you’re waking up when your body’s clock believes you should be sleeping instead.

If it’s possible, try to avoid having to wake up and dive right into a serious task during your body’s biological night.

Other strategies

You could possibly try other countermeasures, like washing your face when you wake up or blasting cold air to perk you up.

Some scientists are even investigating the use of sound, which could include noise or music, to improve a person’s performance upon waking.

But research is very limited on these types of measures.

Whether you regularly experience sleep inertia or not, embracing good sleep hygiene is always a good idea. It can help you get the appropriate amount of rest that you need to function well and feel good.

Consider a few of these strategies:

  • Establish a regular bedtime routine to help you unwind and relax. You might listen to some soft music or read a few pages in a book.
  • Stick to a regular sleep schedule. That is, plan to go to bed at the same time each evening and wake around the same time each morning.
  • Log off from all electronic devices at least 30 minutes before bedtime. Some people find that it’s easier to forego the electronic devices, including tablets, laptops, and even televisions, if they keep them out of the bedroom altogether.
  • Don’t drink coffee or other caffeinated beverages in the evening before bedtime.
  • Keep your bedroom cool and dark, which can help you relax and sleep better.
  • Avoid drinking anything containing alcohol before bedtime, since research suggests it can disrupt your sleep.
  • Don’t eat a big meal close to bedtime. But a light bedtime snack might help, if you’re hungry. Some research suggests that a snack, especially foods that contain tryptophan or affect your body’s melatonin and serotonin levels, might help you sleep a little better.

If you don’t experience sleep inertia very often, or your grogginess upon waking tends to wear off pretty quickly, you probably don’t need to worry about it.

Or you could explore whether a few simple strategies, like drinking a caffeinated beverage in the morning or scheduling a short nap, can help.

If you have trouble shaking off the grogginess and it’s interfering with your ability to get on with your activities of daily living, consult your doctor. You may benefit from seeing a sleep specialist.