The sleep cycle
Light sleep
in non-REM
These are the first stages
of sleep, beginning as you
start to feel drowsy. As you
fall asleep, your muscles relax,
your heart rate slows and
your body temperature
falls. You can easily be
roused from light
sleep.
REM sleep
Your brain is active in
this type of sleep. Your eyes
move rapidly from side to
side but the rest of your
body is relaxed. This is
the time when you
dream.
z
zz
Deep/slow-wave
sleep in non-REM
Your blood pressure falls in
this stage and you sleep more
heavily. You’re hard to wake
from this stage and will be
confused if you’re woken up.
It’s in this stage of sleep
that some people can
sleep talk and sleep
walk.