What is REM Sleep?

Our brain moves through five distinct stages during sleep, one of which is rapid eye movement (REM). 

As the name suggests, REM sleep is characterised by our eyes moving rapidly in different directions. This distinguishes it from non-REM sleep, which accounts for around 75 to 80% of an adult’s average sleep cycle.

REM occurs for the first time within 90 minutes of sleep onset before recurring periodically throughout the night. While the first cycle of REM typically lasts around 10 minutes, it can go on for as long as an hour in subsequent occurrences later in the night. 

The importance of REM sleep stems from its ability to fire the parts of the brain responsible for learning, as well as creating and retaining memories.

Without it, our brains and bodies will struggle to rest, recover, and process experience, leading to a detrimental effect on physical and mental health. For example, research suggests that people who don’t gain enough REM sleep struggle to remember things they learned before falling asleep.

What are the effects of REM sleep?

REM sleep has a significant effect on breathing, heart rate, and blood pressure, all of which will reach similar levels to when we’re awake. Your body temperature will also change, and your limbs and face will twitch.

Most notably, REM sleep comes with an increased chance of dreaming, with the majority of dreams taking place during REM sleep. As muscle relaxation and immobility kick in, our brain prevents our bodies from moving involuntarily while we dream.

Stages of Sleep

The uniqueness of REM sleep means that other stages are often grouped together under the general label of ‘non-REM’ sleep. Nevertheless, there are four additional stages that we pass through before REM sleep, which is why REM is sometimes known as ‘stage 5’.

For the average adult, each stage lasts for roughly 5 to 15 minutes. Older people tend to have longer cycles and less REM, while it’s the opposite for infants, who experience shorter cycles and more REM.

Stage 1: The lightest and most easily disrupted stage of sleep, stage 1 is best understood as a gateway to later stages. It’s characterised by slow eye movements and drowsiness as the body begins to relax. It’s also the stage where people sometimes feel the sensation of falling, which is caused by your brain moving in and out of stage 1.

Stage 2: This makes up around 50% of a night’s sleep. Body temperature decreases and heart rate and brain waves slow, preparing your body for the movement into later stages. Those who power nap should aim to wake up at this stage to avoid the grogginess of awakening during deep sleep.

Stages 3 and 4: These stages involve deep sleep, with an absence of eye movement and muscle activity as your body becomes fully relaxed. Stages 3 and 4 have a restorative effect on muscles, tissues, and the brain, as well as regulating the immune system and producing growth hormones.

Having moved through these stages your body will be ready to enter REM sleep. Following the conclusion of REM, we move backwards through the previous stages until we reach stage 1, before the process begins again. On an average night’s sleep an adult will complete four or five of these cycles; experiencing fewer than this is when the effects of tiredness and sleep deprivation begin to kick in.

How to Get More REM Sleep

If you’re keen to maximise your rest and recovery time, there are a few steps you can take to improve your sleep quality and extend your REM cycle.

1. Establish a Bedtime Routine

Try to go to bed and wake up at a similar time every day (even at weekends!). Your body will quickly acclimatise to your schedule, allowing it to move through the different stages of sleep more naturally and easily.

2. Eliminate night-time interruptions

Loud noises, bright lights, and excessively low or high temperatures can wake you up mid-REM cycle. Muting phones, having the right thickness of bedding, and ensuring blinds or curtains are closed will help avoid interruptions.

3. Avoid Alcohol

Drinking alcohol in the evening can both delay the onset of REM and reduce the overall amount you experience. Even if alcohol can help people sleep, it ultimately reduces sleep quality.

4. Regular physical activity

While a single day of exercise is unlikely to make a significant difference, studies suggest that  incorporating some exercise into your daily routine can increase the amount of REM sleep.

REM Sleep Behaviour Disorder

REM sleep behaviour disorder (RBD) is marked by an absence of the muscle paralysis that usually occurs during REM sleep. In practice, this means that sufferers of RBD tend to physically act out vivid dreams through violent arm and leg movements. Talking, shouting, or crying while dreaming are other symptoms.

RBD can be caused by a range of issues including neurological conditions, withdrawal from drugs or alcohol, and adverse reactions to medication such as antidepressants. Rather than coming and going, the symptoms of RBD will generally worsen gradually over time.

Contact your doctor if you’re experiencing these symptoms, who’ll be able to recommend treatments ranging from various types of medication to altering your sleep environment to ensure safety.

Sleep Health Advice

Feel like you’re always struggling to get enough sleep? You’re not alone, with figures from the NHS suggesting that 1 in 3 people consider themselves to suffer from poor sleep.

Luckily, our sleep archives contain a wealth of advice on healthy sleeping.

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