Tag Archives: Stages of Sleep

The 4 Stages of Sleep

Clinical studies show that there 4 distinct stages of sleep the body goes through. Understanding these stages may help you get a better rest once you know how to work with each stage.

Each of these stages of sleep are categorized by the American Academy of Sleep Medicine!

Non-Rapid Eye Movement or NREM First Stage of Sleep

Phases of sleepClosing your eyes and starting to drift off to sleep but you can be easily woke. It’s during this time that many people think about stressful situations throughout the day preventing them from reaching the stage 2 of sleep. Follow our 16 steps for better sleep to prevent stress from stopping you from reaching stage 2 of sleep. Click Here.

When your woken from this stage it may feel like you never slept at all. On average this stage of sleep last around 10 min. During sleep studies participants claim to have had the feeling of falling which is normal. During this feeling you may physically jolt or jerk suddenly in an effort to stop falling. This state is called, hypnic myoclonia or hypnagogic jerk.


  • Even though you’r actually sleeping in this stage, it’s common to feel like you never slept all if you may wake up for one reason or another.
  • The muscles in your body are not totally relaxed just yet and your eyes start to roll a little bit and some people may slightly open their eyelids a bit.
  • The heartbeat becomes slower and steady and breathing begins to slow down.
  • The brains temperature begins to decrease.
  • Blood pressure begins to decrease.

Melatonin sleeping aids such as Alteril will help you get into the second and third stages of sleep. Once there your body will move into stage 4 of sleep easier and for longer durations.

(NREM) Second Stage of Sleep

This stage of sleep will last about 20 minutes. Humans will spend 45% of their sleep in Stage 2. During this phase the body begins to drift deeper into sleep and you will be harder to wake up. Those with sleep deprivation issues have a hard time reaching stage 2 of sleep.

Although this is a deeper sleep than stage 1 both stage 1 and 2 of sleep are considered to be in the light sleeping category.


  • Heart rate slows and other organs begin to slow as the body prepares to drift into a deeper sleep than stage 1.
  • It’s more difficult to wake during stage 2.
  • The brain begins to emit larger brain waves.

(NREM) Third Stage of Sleep

This stage of sleep is known as delta stage, deep stage or the slow-wave sleep (SWS) stage of sleep.

Similar to stage 2 the body is even less like to respond to it’s outside surroundings, essentially the brain switches off outside stimuli. This stage lasts for longer periods during the first half of the sleep cycle.

Lasting for around 15%-20% of your total sleep time.

The brain transmits what are called delta brain waves at a frequency of about 0.5-4 Hz which makes this stage 3 where in stage 4 the delta waves exceeded 50%.


  • This stage of sleep begins about 45 minutes after you fall asleep.
  • The brain waves slow but become much larger.  
  • It is during stage 3 that the final stage (REM) sleep begins.
  • Difficult to wake up. The body is in deep sleep mode and blocks out most exterior noises and movements without reacting or waking up.
  • When woken during stage 3 you will be disoriented for the first few minutes as the brain and body try to adjust.

Stage 4 for sleep is know as REM

This stage (Rapid Eye Movement) is the deepest state the body can be in during the sleep cycle. This level of sleep will start around 90 minutes after you’ve been asleep and accounts for 20-25% of total sleep time. The body will cycle in and out for REM stage throughout the night.

Stages of Sleep

Image is courtesy of centerforsoundsleep.com

During this REM stage the category of sleep disorder called “Parasomnias” is more likely. Disorders like, wetting the bed or night terrors, sleep-walking and talking in your sleep can occur.