What is REM Sleep and How Much Do You Need?

6 Min Read | By Nat Took

Last Modified 2 October 2024   First Added 6 August 2021

This article was written and reviewed in line with our editorial policy.

REM sleep definition:

A kind of sleep that occurs at intervals during the night and is characterised by rapid eye movements, more dreaming, and faster pulse and breathing.

Source: Google Dictionary

Sleeping isn’t just about laying down and relaxing in bed. Your body and brain have a lot on whilst you get your shut-eye. In fact, you go through various stages of sleep when you rest at night. It’s quite an intense process, and during these cycles, you’ll go through NREM (non-rapid eye movement) and REM (rapid eye movement) sleep. In this post, we’ll take a look at REM sleep, how much REM sleep you need, and why it’s so important for your health.

What is REM sleep?

REM sleep stands for rapid eye movement. During this type of sleep, your eyes move rapidly, but no visual information is sent to the brain. During REM sleep you can have intense dreams, as your brain is more active. On the other hand, NREM is non-rapid eye movement, your eyes do not move. It’s during NREM that deep sleep occurs.

Many people confuse REM sleep with deep sleep but they’re different. Deep sleep occurs during the non-REM sleep, not during REM.

How much REM sleep do you need?

In total, an adult needs around 90 minutes of REM sleep a night. This should work out as between 20-25% of your typical 7-9 hours of sleep a night. The required amount of REM is much higher in infants who need about 50% of REM sleep.

When does REM sleep occur?

REM sleep normally happens after you’ve been asleep for about 90 minutes. You have several stages of this type of sleep each night, going in and out of REM and NREM sleep. Your first period of REM normally lasts for 10 minutes, and each REM stage that follows gets longer. The last stage of REM can be as long as an hour.

What are the signs of REM sleep?

You may not be able to tell if you’re in REM sleep (as you’re asleep at the time!), but you can tell if someone else is in a REM sleep stage. Signs of REM include:

  • Eyes moving rapidly under the eyelids
  • Sexual arousal can occur
  • Breathing becomes fast and irregular

Other signs that you’ll not be able to see but can happen in the body during REM include:

  • A change in body temperature
  • Heart rate increases to near waking levels
  • The brain increases oxygen consumption
  • Blood pressure increases

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Why is REM sleep important?

REM sleep is important because it is a key part of the sleep process as it helps develop your learning, memory, emotions, and central nervous system. Let’s look at these reasons in more detail…

1. Learning and memory

There are studies that suggest that if people are unable to get enough REM sleep, they have difficulty with their memory – both forming memories from the day before and picking up new skills the day after. One study showed that not getting enough REM for just 4 days affected cell proliferation in the part of the brain that contributes to long-term memory in rats.

2. Central Nervous System (CNS) development

It’s thought that REM sleep is important for brain development in babies. One study suggests that REM is responsible for the neural stimulation that is needed to develop mature neural connections.

REM sleep is also so essential as its crucial functions mentioned above are different to those of NREM and deep sleep. Therefore, getting the correct amount of all types of sleep is necessary for your well-being.

3. Emotional regulation

As we learn more about sleep, scientists have discovered that it plays a vital role in emotional processing while we are unconscious, but also while we are awake. Sleep deprivation in general can make us more sensitive to emotional stimuli and therefore, less able to cope with everyday stressors.

When looking specifically at REM sleep and emotional regulation, researchers found a significant link between the two. Both REM percentage (amount of time in REM) and REM latency (the time it takes to reach REM sleep) had a correlation with difficulties in emotional regulation, including lack of behaviour control and difficulty recognising emotions.

Sleep problems and musculoskeletal pain

What happens if you don’t get enough REM?

Not getting enough REM can have negative effects on your overall health. Various research has linked a lack of REM sleep to:

  • Migraines
  • Reduced coping mechanisms
  • Weight gain
  • Changes in mood

How to increase REM sleep

If you’re worried about whether you’re getting enough REM sleep, it’s important to know you cannot improve just your REM sleep quality. You will need to make holistic changes to your sleep routine, so these methods are tips for sleeping better, which will have a knock-on effect.

1. Have a bedtime routine

Firstly, having a good bedtime routine, which prepares your mind and body for rest can help your overall sleep, and help reach REM sleep. By getting your full 7-9 hours in bed, you can maximise the amount of sleep you get, which can increase the number of REM phases. It’s also important to reduce waking during the night.

2. Improve sleep environment

Although you may not be able to control this all the time, if you ensure your sleep environment is right for you, this should help you to sleep through the night thus, helping you get your recommended amount of REM sleep. So, make sure your room is at a comfortable temperature, use blackout blinds or an eye mask if there are bright lights outside, and even use earplugs if you’re in a noisy area.

3. No alcohol before bed

One of the best ways to improve your REM sleep is to avoid alcohol before bed. Alcohol may help you fall asleep quicker, but the quality of your sleep is impacted. Studies have shown that alcohol intake both increases REM latency and suppresses REM sleep, especially in the first half of the night.

4. Quality sleep

The best way to improve your REM sleep is to simply get enough quality sleep. It’s an important part of your nightly sleep cycles, which can affect your overall health. Sleep is important for your well-being, so don’t let it slip and try to make sure that you’re getting enough! For comprehensive tips on improving your sleep experience, visit our guide on how to sleep better at night. 

What happens if you get too much REM sleep?

More REM sleep isn’t the answer to better sleep, in fact, too much can make you fatigued the next day. When you sleep for an exceptionally long period in the REM sleep stage, it could be a sign that you’re sleep-deprived. It’s also closely linked with depression – One sleep study found for people living with depression, REM sleep comes on quicker and lasts longer than normal. If you aren’t getting restful sleep and have low mood, it’s important to reach out to your GP to explore treatment options.

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