11 Jun 2019

What is REM Sleep?

It’s easy to think that sleep is just one long period of unconsciousness that we go through each night. We get into bed, close our eyes and drift off, only to wake the following morning.

However, sleep is actually made up of a full cycle of four stages which repeat several times throughout the night. These stages are known as REM and Non-REM sleep.

You’ve probably heard the terms “sleep cycles” and “REM sleep” bantered around over the years, but what do they actually mean?

The phases of sleep

Throughout the night, your body experiences a series of cycles that last around 90 to 110 minutes. Each cycle is made up of two phases: Non-REM and REM Sleep.During each phase, you experience the following stages:


(1)   Stage 1 (N1)

The initial light sleep stage only lasts for around 5 to 10 minutes, and is where your body slowly relaxes as your temperature begins to slowly fall.

(2)   Stage 2 (N2)

After this, you enter the moderate sleep phase which lasts around 30 to 40minutes.

(3)   Stage 3 (N3)

Referred to as slow wave sleep, during this final Non-REM phase, you enter into a deep sleep where your body completely relaxes, eye movement ceases, your heart rate slows down, and it becomes difficult to wake as your sensitivity to light and sound decreases.

It’s during this stage where you get the best quality sleep. 

Non-REM 2

REM Sleep

REM (Rapid Eye Movement) Sleep is the final part of the complete cycle, and is unlike the above three stages because your brain becomes very active, and your body becomes almost completely paralysed. Breathing also becomes shallow and irregular, while the heart rate and blood pressure rise.

This phase is called REM Sleep because your eyes dart in all different directions while your mind begins to dream. It’s believed that it’s during this stage where the brain is revitalised, which benefits emotion regulation, learning and memory processing.

REM Sleep can last only a short amount of time, to around 30 to 40 minutes.When both sleep phases (Non-REM and REM) are complete, it’s considered a full cycle, which repeats in full again around four times throughout the night until you wake. Over the course of the night, the amount of time we spend in each specific stage of sleep changes.

The number of hours we sleep ensures that we give our bodies and brains enough time to progress through these cycles sufficiently enough to gain quality sleep to feel well-rested the following day.

To read more, see our blog: How to sleep for longer

REM Sleep 2

Want to learn more about improving your overall sleep?

In a face-paced environment today where it’s common to deprive ourselves of sleep, we should all be aiming to get the most out of our sleep to remain healthy and happy each day.

At ResSleep, we have created a free eBook available to download right now, called the 8 Ways To Sleep Better Tonight. Inside, you’ll be able to read about the eight best ways to improve your sleep in order to get the best rest out of every night.

Book A Sleep Consultation

If you wish to talk to someone about your current sleep patterns or find out more about having a sleep test, you can book a sleep consultation today and put your mind at ease.




  1.     Sleep: Facts and hygiene. The Department for Health and Ageing, Government of South Australia.  
  2.     Healthy Sleep Habits. Heath Direct, Australian Government Department of Health.
  3.     Teenagers and Sleep. Better Health, Victoria.
  4.     The Government is worried you’re not getting enough sleep. ABC News, Nov 2018.
  5.     Experts reveal new sleep requirements for different age groups. The Sydney Morning Herald, Feb 2015.