Live Better
 
 

What really happens during each stage of sleep?

A closer look at the science of sleep, and what happens in our bodies during our slumber.

Child sleeping

We all know how important it is to get a good night’s sleep, but what’s really going on when the lights go out? We break down the five stages of sleep to find out.

Stage 1: Drifting off

Heavy eyelids and a droopy head are sure signs you’re drifting off into the first stage of sleep. Best compared to daydreaming, the Alpha state is a restful place most familiar to those who practice meditation. If you’ve ever woken to a sudden leg jerk or spasm it’s because during this stage we experience something called hypnogogic jerks. We can also experience hypnogogic hallucinations, the most common being a sensation of falling.

The first stage of sleep usually lasts 5-10 minutes with the average person taking 7 minutes to fall asleep.

Stage 2: Light sleep

During stage two our body temperature begins to drop and our heart rate starts to slow. We become disengaged from our surroundings and our brain activity becomes slower, with occasional bursts of rapid brain waves. In this stage our memory is ‘backed up’ and short-term memories can become long-term memories.

Light sleep lasts around 20-25 minutes.

Stage 3: Transitional

The transition from light to deep sleep happens during the third stage. Brain activity begins to slow and we become much more difficult to wake.

This stage can last between 20-40 minutes.

Stage 4: Deep sleep

Stage four is the deepest stage of sleep and the most restorative. Our muscles relax, breathing becomes rhythmic, tissue repairs and growth hormones are released to assist muscle development. This is usually the stage that sleepwalking and bed-wetting occurs.

Deep sleep lasts for 20-40 minutes, during which we’re extremely hard to wake.

Stage 5: REM (Rapid Eye Movement)

REM sleep is the dreaming stage of our cycle – it’s when our brains are most active yet our bodies paralysed. If woken during REM sleep, it’s likely we’ll remember our dreams. Muscle paralysis protects us from harming ourselves. If you’ve ever felt like you can’t run during a dream, it’s because you literally can’t.

The REM stage can last between 10-60 minutes.

Contrary to what you’d suspect, our sleep stages don’t progress in a purely linear sequence. It begins with drifting off, then progresses to light sleep, before transitioning into deep sleep. After deep sleep we transition back to light sleep before beginning REM sleep. After REM, we usually return to light sleep. This cycle goes on approximately 4 or 5 times throughout the night.

Typically REM sleep happens 90 minutes after falling asleep. The first cycle of REM is short and gets longer with each cycle, which means our deep sleep happens at the beginning of the night. This is why it’s important to have long periods of sleep, to get through all stages, so our bodies can rejuvenate and stay healthy.

Recommended Reading

Wellbeing

Could an online mental health tool help you?

Black Dog Institute psychologist Dr Peter Baldwin explains. Read more

Wellbeing

Chemo at home: Liam’s story

For Liam, having chemo at home has made all the difference. Read more

Wellbeing

Staying alive down under

How to stay healthy in Australia. Read more

Wellbeing

Worried that you’re gaining weight at Uni?

We’ve got simple pro-active approaches to a common issue. Read more

Wellbeing

How to cope with winter sadness and depression

Psychologist Morag Paterson shares how to feel better. Read more

Wellbeing

Does calling home make you more homesick?

Here are tips to deal with feeling homesick. Read more

youtubetwittersign-up-userArtboard Copynp_phone_503983_000000download_red4xdownload_red4x copyArtboardmember-offer-starLogoMedibank - Logo - ColourOval 5Instagram iconicon-editdownload_red4x copygive-back--spinesgive-back--moneygive-back--massagegive-back--likegive-back--jointgive-back--emailgive-back--dislikedownload_red4xdownload_red4xGroup 5filter-iconfacebookMobile Navcheckcarret-upcarret-rightcarret-leftcarret-downGroup Copy 2arrowarrow-circleanimated-tick