Your Sleep Cycle: About REM and The Stages of Sleep

But to get to that point, we need to go through each of the sleep phases. We can break down the stages of sleep into two main categories: REM (rapid eye movement) and NREM sleep (non-rapid eye movement).

This article explains the different sleep cycle stages, how they work, and why they matter.

A complete sleep cycle lasts about 90 to 110 minutes. You’ll go through three stages of Non-REM sleep and, finally, REM sleep¹.

Known as ‘rapid eye movement’, because your eyes dart in different directions while closed, this form of sleep usually starts about 90 minutes into a cycle. REM cycles are associated with higher levels of brain activity, and dreaming¹.

NREM sleep, meanwhile, makes up about 75% of your total sleep time – and consists of progressively deeper stages of sleep.

Once you’ve completed an entire sleep cycle, you’ll start again at stage one and repeat until you wake up¹.

Here are the stages of sleep in a typical, full cycle:

The first two sleep phases are typically considered light sleep. You’ll spend around half the night in stage two. This acts as an extension of the first stage of your natural sleep cycle, and your breathing, eye movement, heartbeat and muscle activity will continue to slow down³.

Your body temperature will also start to fall during stage two sleep³.

During stage two, you may experience what’s known as ‘sleep spindles’. These are short bursts of brain activity that occur every three to six seconds and last just 0.5 seconds each time. They are thought to block out external stimuli which might otherwise cause you to wake up.

Like sleep spindles, K-Complexes are short, sudden peaks of brain activity that help block out triggers which would otherwise cause us to wake.

While the first two stages of the sleep-wake cycle are classed as light sleep, the third stage is much deeper¹.

Deep sleep is sometimes known as ‘slow-wave sleep’ because of the long, slow delta waves produced by our brains during these final two sleep stages⁵.

You’ll usually enter the third stage within an hour of falling asleep. If you wake up at this point, you’re more likely to feel groggy for around an hour afterwards⁵.

By contrast, during light sleep stages we are much easier to wake up.

If you’re struggling to get the sleep you need, there are multiple, small changes you can make to your lifestyle that might help improve your resting hours. You should also talk to your doctor if you have any questions about your sleep.

Make sure you go to sleep and get up around the same time every day - even on weekends and vacations.

Try to clear your head of excessive thoughts before going to bed. You could try meditating, or simply make a to-do list for the following day, so you have everything noted down and don’t have to worry about remembering everything.

Aches and pains, especially in our backs or legs, can often stop us from getting a restful night’s sleep. Over-the-counter medication like Tylenol® PM can help relieve minor aches and pains to help you get a better night’s sleep. If pain isn’t what’s keeping you awake at night, you can try Simply Sleep®, a non-habit forming medication that helps you rest easy.

Are your pillows and mattress suitable for you? Making sure your bed is comfortable can be vital in helping you get a good night’s sleep. You can also create a better sleep environment by getting the lighting and temperature right for you, and taking steps to keep out loud noises.

Keeping active is a great way to bring on a good night’s sleep. Just avoid doing it too close to bedtime!

Many of us turn to caffeine to help us get through a long day, but it’s not a good idea to drink caffeine close to bedtime – as it can keep us awake.