You know the feeling. You spend a full eight hours in bed but still wake up foggy, flat or just not yourself. While getting enough sleep matters, the kind of sleep you’re getting plays a big role too. One stage that often gets cut short is REM sleep, which is closely linked to how you think, feel and learn during the day.
At nib, we’re here to help you understand your health and make small changes that add up. That’s why we spoke with Dr Aliza Werner-Seidler from the Black Dog Institute to unpack what REM sleep really does, why it matters and how to support it naturally.
What is REM sleep?
Sleep comes in two main forms: non‑REM sleep and REM sleep. REM stands for 'Rapid Eye Movement’ and it’s the stage when your brain is most active. You cycle into REM roughly every 90 minutes, with each REM period getting longer as the night goes on. During REM sleep, you tend to dream more vividly and your heart rate and breathing can change depending on what’s happening in those dreams. This activity is a sign that your brain is hard at work processing emotions, memories and information from the day.
Non-REM sleep, on the other hand, has three stages that move from light sleep into deeper, more restorative sleep. These stages help your body physically recover, while REM sleep focuses more on mental and emotional restoration.
“REM sleep is essential for mental restoration,” says Dr Aliza. “It plays an important role in memory consolidation, learning and emotional regulation.”
How much REM sleep do you need?
For most adults, REM sleep makes up around 20% of total sleep time. If you’re sleeping for seven to eight hours a night, that usually works out to roughly 90 minutes of REM sleep.
Our REM needs change over time. Babies and children spend a much larger proportion of their sleep in REM as their brains rapidly develop, while adults gradually spend less time in this stage.
How do you know if you’re getting enough REM sleep?
According to Dr Aliza, the timing of your sleep matters just as much as the total hours you get.
“REM sleep tends to become progressively longer later in the night,” she explains.
That means late nights, early alarms or frequently disrupted sleep can all cut it short, even if you technically spend enough hours in bed. When REM sleep is cut short, your body tends to compensate. You’ll often move into REM sleep earlier and stay there longer the next time you rest. This catch-up effect is known as REM-rebound.
“If you’re regularly waking up unrefreshed, feeling mentally flat or finding it harder to focus, it may be a sign that your overall sleep quality, including your REM sleep, isn’t quite where it needs to be,” Dr Aliza explains.
What happens if you don’t get enough REM sleep?
REM sleep plays an important role in how your brain processes information overnight. It helps with emotional regulation, learning and memory, which support the mental work you do during the day.
When REM sleep is regularly cut short, that processing doesn’t work as smoothly. Over time, this can look like feeling more emotionally reactive, having trouble concentrating or finding it harder to retain new information.
Dr Aliza explains that REM sleep is especially important for how our brains learn and adapt.
“REM sleep helps strengthen procedural memory, which is the type of memory involved in learning new skills,” she says. “It also supports problem solving and how the brain makes sense of information over time.”
Without enough REM sleep, these processes have less opportunity to do their job, which can subtly affect how focused, flexible and mentally sharp you feel during the day.
The sleep toolkit: four ways to support healthy REM sleep
Even though you can’t force your body into REM sleep, you can create the right conditions for it to happen naturally. While sleep can look a little different for everyone, Dr Aliza suggests four practical ways to help you get started with improving your overall sleep:
Stick to a rhythm: Going to bed and waking up at similar times each day helps regulate your internal clock, making it easier to progress through all sleep stages,
Be mindful of stimulants and alcohol: Caffeine, alcohol and nicotine can all delay or disrupt REM sleep. Cutting back, especially close to bedtime, helps your brain wind down more naturally.
Set up your sleep environment: A cool, dark, quiet room supports deeper, more continuous sleep. Switching off screens before bed and establishing a calming wind‑down routine can also help. It signals to your mind and body that it’s time to rest.
Check for underlying sleep issues: If sleep still feels like a struggle, it might be worth having a chat with your GP to see what else could be going on. nib members can also access consultations with Australian-based medical doctors via nib Telehealth, making it easier to get advice and next steps from home.
Still tossing and turning after trying these tips? Dr Aliza recommends taking the pressure off.
“If you can’t fall asleep after about 20 minutes, try getting out of bed and doing something calm, like reading. When you feel sleepy, go back to bed. This stops your brain from associating your bed with the stress of staying awake, helping you return to sleep with a fresh start.”
How nib can help support better sleep
nib foundation has supported Black Dog Institute’s Sleep Ninja® app, which allows young people to learn about sleep in a fun, interactive way under the guidance of the ‘Sleep Ninja', who acts as a sleep coach to guide the young person towards mastering their sleep. The app helps young people develop healthy sleep habits and improve sleep quality.
Dr Aliza Werner-Seidler is a Scientia associate professor and clinical psychologist at the Black Dog Institute. She has a PhD from the University of New South Wales and has undergone post-doctoral training at Cambridge University.
The information on this page is general information and should not be used to diagnose or treat a health problem or disease. Do not use the information found on this page as a substitute for professional health care advice. Any information you find on this page or on external sites which are linked to on this page should be verified with your professional healthcare provider.
