Sleep Cycle Stages – What happens While You Sleep

In General Information by JGrahamLeave a Comment


Sleep Cycle Stages


When we sleep, we typically go through several cycles of sleep. And each one of these stages consists of 4 different stages of sleep. Let’s take a trip through Sleepy Town and go through the differences of these stages and what we know about each of them.

NREM 1


This stage occurs after you have decided to sleep and your eyes are closed.

  • Breathing gradually becomes more regular and the heart rate begins to slow.
  • This is the time where you get that crazy feeling that you are falling and twitch awake.  
  • A person awakened during this period will often believe they haven’t slept.

Fun fact of the day: this twitch is called a hypnagogic jerk, and are quite common.

NERM 3


This sleep stage refers to the combined stages of what was previously separated into Stage 3 & 4 sleep.

  • This stage typically starts 35-45 minutes after falling asleep.
  • As electroencephalograms show, our brain waves slow down and become larger
  • At this point, you sleep through most potential sleep disturbances (noises and movements) without showing any reaction.
  • If you actually wake up during NREM Stage sleep, there’s a high probability you are going to feel disoriented for the first few minutes.
  • Other names for this stage include “slow-wave sleep” and “Delta sleep.”

NREM 2


 When NREM Stage 2 sleep kicks in, things get serious!

  • Stage 2 sleep, which usually lasts about 20 minutes, is characterized by a slowing heart rate and a decrease in body temperature.
  • Your body reduces its activity to prepare you to go into a deep sleep.
  • Your blood pressure, as well as other metabolic functions, slow down.
  • It becomes harder to wake you up.
  • Your brain starts to emit larger waves.

The 2 first stages of NREM Sleep together are often referred to as light sleep. 

REM SLEEP


This is the final stage of a standard sleep cycle. The first Rapid Eye Movement sleep stage lasts around 10 minutes and usually happens after having been asleep at least 90 minutes.

  • As its name indicates, your eyes move rapidly in all directions during Rapid Eye Movement sleep.
  • It is during this stage of sleep (the deepest) that powerful dreams usually happen. Same goes for sleepwalking and bedwetting episodes.
  • This stage is also characterized by an increase of the heart and respiration rates, and their rhythms may become irregular.

Leave a Comment