The first stage is dozing off, the next
sleep, then comes deep
sleep, and finally REM
sleep. These stages will
be explained in more detail below.
If you sleep for 8 hours a day, you will on average get 2 hours of deep
sleep, 2 hours of REM sleep and 4 hours of light sleep. The sleep
stages replace each other in phases of approximately 1.5 hours, and
most people repeat it
4-6 times during the night. During the REM phase
of sleep, intense activity occurs on the brain, and dreams are much
more frequent and vivid than in the other phases.
Quality of sleep is divided in to two types. The subjective sleep
quality is the feeling of being rested and having had a
sleep. The more scientific, objective
quality of sleep is determined by
measuring the different phases. How long a person is in the deep stages
of sleep and number of times they wake up during the night is
You need all four stages of sleep,
again and again. It is not possible to cheat and skip the lighter
phases, although scientists say that the more tired you are,
the more you will get out of your sleep.
1- Dozing Off
This stage is sometimes referred to as somnolence or drowsy sleep.
Your eyes close and your body
finds peace under the covers. In this
stage you doze off and wait for dreams to come. There is still a long
way to dreamland, however. First of all, brain waves need to undergo a
cycle. Dreams are to be found at the end of this, in the
last stage: the REM sleep.
This first phase is a transitional one, where 50% of people will say
“but I was awake when you woke me up!” while the remaining 50% will say
“no, I was sleeping” if awoken and asked “are you awake?”
When we transition from drowsy sleep to actual sleep, brain waves
change from alpha waves to theta waves. Electrical
currents in the
brain fall from 8-12 hertz to 4-7 hertz.
Muscles in your body become relaxed and you might experience small,
involuntary kicks and jerks of your limbs. These movements
likely caused by the body having a hard time controlling the transition
from being tense and awake to being completely relaxed.
This first sleep phase is usually quite short and after 5-10 minutes,
you start slipping into the second phase of sleep. When we are there,
there is no doubt about it: sleep has come.
2 – More than Sleepy
In this stage of sleep people
will always answer ”I’m sleeping” when
asked if they are awake. Brain waves start showing characteristic signs
of sleep. Although the sleep is still light, they slow down and EEG
measurements show softer and larger fluctuations. The so-called sleeps
spindles occur every once in a while. These spindles are bursts of
brain activity that helps keeping us asleep.
shown on an EEG
device they appear like small earth quakes. Sleep spindles are
sometimes referred to as sigma
bands or sigma
waves. These are the most
common characteristic sign of the onset of stage 2 sleep, along with
which suppress cortical arousal in response to stimuli.
During the second stage of sleep a person no longer has any connection
to their consciousness. In adult people the second stage takes up
approximately half of the night’s sleep.
3 – The Deepest Calm
The third phase of sleep is
sleep. Brain waves are very slow,
and delta waves of 1-2 Hertz occur. This is where you truly sleep and
your body regenerates.
It is during this stage that a person may sleep walk, talk in their
sleep or wet
their bed. Awoken from this stage, people will feel
extremely tired and drowsy. Waking up not knowing where you are is
common. It is also much harder to wake a person up from this stage, and
the brain will work on half power for about ½ an hour after awakening.
Sometimes people claim that they can slip directly into this stage of
sleep, for example parents with infants and elite soldiers.
is that when you are tired you sleep better, and are closer to the
later stages of sleep from the beginning. These people simply utilize
their sleep better and achieve true sleep more quickly.
4 – Only In Your Dreams
REM – rapid eye movement - is the most well-known stage of
where the most vivid dreams occur.
first three stages of sleep are also referred to as N-REM- non
rapid eye movement. REM is significantly different from the other
stages, in that the eyes
move back and forth, and brain waves are more
similar to those of a waken person than those of the other sleep
stage is also known as paradoxical
sleep, since the brain
seems to be awake in a sleeping body. It is easy to wake up from REM
sleep, which is why it is so common to
wake up during a vivid dream.
This dreamy stage normally accounts for 20- 25% of a night’s sleep
When you have gone
through all four stages the
cycle stars over. Dreams stop in the REM
stage and you return to the first stage. The sleep cycles have almost
the same length during the night. The different stages, however, change
in character and length. After the first cycle, the deep,
sleep stages are shorter and the REM stage becomes longer. Towards the
end of the night the REM sleep takes up most of the cycle and the deep
sleep is pretty much over.
of Sleep and Snoring
- Snoring associated with
apnea occurs less in stage 3
- Ordinary snoring occurs
most in stage 3, but is also likely to occur
in stages 1 & 2
- Ordinary snoring does not
normally occur in the REM stage
- Snoring associated with
sleep apnea is more frequent in the REM stage
to How to Sleep Better
to the Snoring