There are few things more frustrating than waking up feeling groggy after what you hoped would be a refreshing and revitalizing night’s sleep. Maybe your mind was racing all night, or you were suffering from night sweats, or maybe you just didn’t get enough rapid eye movement (REM) sleep.

We cycle through several sleep stages each night multiple times. These sleep stages can be broadly categorized into non-REM (NREM) sleep—in which we spend about 75 percent of our sleeping time¹, and includes deep sleep—and REM sleep. REM sleep is the last phase of the sleep cycle. In this phase, our eyes start moving rapidly, our brain becomes more active, and we enter the phase where most dreaming occurs (although it can happen in other phases, too), per Haunani ‘Iao, PsyD, president and founder of ‘Iao Mind Body Health.

“REM sleep helps lock in newly learned behaviors…People also make new connections between loose and unrelated ideas during REM sleep, which is why dreams can seem so random sometimes.” —Alex Dimitriu, MD

“Our brain is active for all sleep stages, and is the most active during REM sleep, when it resembles the brain activity of an awake brain,” Dr. ‘Iao explains. “Our heart rate changes, there is more blood flow, and breathing can be shallow or irregular. Our bodies are also paralyzed during this stage to protect us from acting out our dreams.”

Generally speaking, REM sleep is important for our health and well-being; it helps us consolidate memories² and is generally considered to help restore our bodies and minds³. So how do you get REM sleep (or more of it) to maximize the benefits? Here’s what experts have to say.

How many hours does it take to get into REM sleep?

Sleep occurs in stages, so we cycle in and out of REM sleep throughout the night. According to Tracey Martin, a sleep and insomnia expert and founder of TM Insomnia Treatment, it takes around an hour-and-a-half for us to enter REM sleep for the first time after falling asleep.

“Your first REM cycle generally starts 90 minutes after you fall asleep and it is quite short, lasting about 10 minutes,” Martin explains. “The REM stages get progressively longer as you cycle through the different stages throughout a night, with your last REM stage lasting approximately an hour.” After each cycle ends, your body returns to NREM sleep before cycling back to REM another 90 minutes or so later.

Alex Dimitriu, MD, psychiatrist, sleep medicine specialist, and founder of Menlo Park Psychiatry and Sleep Medicine, adds that because the REM stages are shorter when you first fall asleep and get longer later in the night and into morning, not getting enough sleep means you’re probably missing out on prime REM sleep.

“Aim for eight hours of sleep, and be sure to get a minimum of seven hours,” he advises. “And keep regular sleep and wake hours—sleep loves rhythm and regularity.” It’s also important to figure out what your individual sleep need is, too. While the range for the average adult is 7 to 9 hours, you may fall on the longer end of the spectrum and need 9 hours to feel fully rested.

Why is REM sleep important?

Your brain is so active during REM sleep that you’re actually experiencing a boost of neural activity, which Dr. ‘Iao notes can be beneficial for “important functions such as memory⁴, learning, performance, and problem solving.” Dr. Dimitriu agrees, adding that REM sleep helps our brains retain new information and connect different ideas.

“REM sleep helps lock in newly learned behaviors, so if you are learning how to ski, and you sleep and get good REM sleep, you will ski better the next day,” Dr. Dimitriu says. “People also make new connections between loose and unrelated ideas during REM sleep, which is why dreams can seem so random sometimes.”

Given these brain-friendly benefits, it’s no surprise people suffer from irritability and mood changes⁵ and feel generally unwell when they don’t get enough rest. While a bad night every now and then is nothing more than a temporary pain, Dr. ‘Iao says missing out on REM sleep consistently can have serious consequences for your health. “When this process is interrupted, there are implications for disorders such as Alzheimer’s⁶, Parkinson’s⁷, and psychiatric disorders like depression⁸ and schizophrenia⁹,” she says.

Some people dealing with sleep deprivation also experience what’s known as REM rebound, a phenomenon in which you enter REM sleep earlier in the night and experience it to a deeper, more intense degree—at the expense of deep sleep. So getting enough REM sleep will keep your rest schedule in balance.

How much REM sleep do you need?

“The average healthy adult sleeper will spend approximately 25 percent of their night in REM sleep,” Martin says. That means if you get the recommended eight hours of sleep a night, you should be getting a solid two hours of REM sleep.

What causes lack of REM sleep?

There are a few potential reasons why people miss out on REM sleep. One of the simplest: not sleeping enough, period. If you’re not getting enough sleep overall, your body won’t have enough time to spend in the REM stage. So experts recommend first and foremost making sure you’re getting at least eight hours of sleep a night (or meeting whatever your sleep need is).

But a lack of sleep isn’t the only reason you may not be getting enough REM sleep. Both Martin and Dr. Dimitriu say that alcohol and other sedatives, including sleeping pills, can negatively impact the amount of time you spend in the REM stage. Martin explains that many sedatives (like alcohol) “can fragment your deep NREM and REM sleep¹⁰ and lead to you waking up feeling tired and groggy despite potentially sleeping a long time.”

Interestingly, stimulants like caffeine can also keep you from spending enough time in the REM stage each night. “Caffeine works by blocking the part of your brain that feels sleepy and it can linger in our body for longer than you may suspect,” Martin explains. She suggests limiting your caffeine intake to twice daily, and not consuming any caffeine after lunch.

Sleep apnea—a disorder where your breathing stops and starts while you’re asleep¹¹—is another big culprit, says Dr. Dimitriu. “Because the muscle system goes offline for REM sleep, breathing can get worse too,” he explains. “This is why people with sleep apnea suffer from impaired REM sleep as well.” Other sleep disorders like insomnia—where you either can’t fall or stay asleep— can impact your REM sleep, Martin adds. “If you have sleeping issues where you wake too early in the morning and cannot get back to sleep, then you may be missing out on the majority of your REM sleep needs.”

Tips to increase your REM sleep

There are a few steps you can take to improve the amount of REM sleep you get each night and in turn improve the quality of your sleep overall. Not every tip will work for every person, so you may need to try a few to find what works for you.

1. Make sure you’re getting enough sleep, period

The most important thing anyone can do to improve sleep—and in turn, improve the amount and quality of REM sleep you get—is simply making sure you get enough of it. Most experts suggest adults get between seven and nine hours of sleep a night, with eight hours being the ideal for most. Martin advises planning in advance—say by setting a bedtime alarm—to “make sure you are allowing yourself time to achieve that amount of sleep.”

2. Set—and stick to—a sleep schedule

One of the best ways to ensure you get enough sleep each night is by setting a sleep schedule and actually adhering to it. Dr. ‘Iao suggests you go to bed and get out of bed at the same time each day, even on weekends, to keep things consistent. “This will increase your sleep drive which helps you to fall asleep and stay asleep all the way until your wake time,” she says.

3. Strengthen your circadian clock

Another way to improve sleep is by focusing on your personal circadian clock, “which regulates your sleep-wake cycles and helps you stay awake during the day,” according to Dr. ‘Iao. Sticking to your set sleep schedule helps, but she suggests exposing yourself to sunlight soon after waking up—since light exposure is an important trigger that tells your body to be awake¹²—and getting some physical activity each day as well.

4. Make your bedroom more sleep friendly

Having a sleep space that’s designed with, well, sleep in mind is another factor that can help increase the amount of sleep you get each night. (This is an important aspect of sleep hygiene, meaning the various lifestyle practices that can help improve your sleep.) Since people typically sleep best in dark rooms Martin suggests making your bedroom “dark, cool and quiet to get a better chance of sleep.” She also says keeping electronics outside of the bedroom can help as well, since the blue light exposure might affect your body’s circadian clock¹³, which might make it harder to fall or stay asleep. (And doomscrolling before bed isn’t great for your stress levels, either.)

5. Keep non-bed related activities out of the bedroom

Dr. ‘Iao says you should reserve your bedroom solely for sleep and sex. That means keeping other activities like studying, working, and eating outside your room. “We want to strengthen the bed and bedroom to be a strong cue for your brain and body to sleep,” she says.

6. Stay active during the day

According to Martin, “being regularly physically active is important for maintaining good sleep quantity and quality¹⁴,” so it’s important to stay active and move your body every day. She also suggests coupling that activity with a healthy diet, which can “ensure you get all the essential vitamins and minerals that are needed to achieve and maintain healthy sleep.” (Even better if you nosh on some foods that make you sleepy before bed.)

7. Avoid unnecessary naps

When you’re feeling overly tired it can be so tempting to squeeze in some extra shut-eye with a nap, but Dr. ‘Iao advises against napping under most circumstances. If you want to nap, most sleep specialists advise up to 30 minutes for a quick power nap. “Any longer and this will interfere with your ability to fall asleep and stay asleep.” (Here are some other tips to help you optimize your nap without ruining your sleep later.)

8. Limit your intake of alcohol and other substances near bedtime

Dr. ‘Iao and Martin both suggest avoiding alcohol use two hours before bed, as it can easily disrupt your sleep. “Alcohol can induce sleep,” Dr. ‘Iao explains. “However, once the effects of alcohol are processed by your liver, your brain and body will awaken, and you will have difficulty falling back asleep.” Martin adds that substances like caffeine and nicotine can also negatively affect your sleep and prevent you from entering the “deeper NREM and REM stages of sleep.”

When to seek care from a doctor

If your daily life is affected by your lack of sleep, it may be time to speak to a doctor. Dr. Dimitriu suggests that anyone who wakes up multiple times each night and doesn’t feel rested in the morning should speak to a doctor, as should people who experience sleepiness when inactive or during focused activities like driving. Similarly, people who rely on large amounts of caffeine to get through the day may benefit from medical advice as well.

—reviewed by Angela Holliday-Bell, MD