STAGE 3

The body is paralysed during this stage of sleep - only the eyes move (and move so rapidly that you can see them moving through closed lids)

STAGE 5

The stage of sleep that you are only in once during the night

STAGE 1

The stage where the EEG shows beta waves (as also shown when awake - but paradoxically this is the deepest stage of sleep)

STAGE 5

The stage where the EEG shows sleep spindles and K-Complexes (brain activity due to muscle activity and external noises)

STAGE 2

AKA SWS (slow wave sleep) as at least 50% of the EEG shows long, slow delta waves

STAGE 4

You are easily awoken in this stage of sleep, although minor noises probably won't wake you up

STAGE 2

Growth hormones are secreted and your heart rate, blood pressure and temperature are at their lowest in this stage of sleep.

STAGE 4

You may experience a hypnogogic state (a feeling of falling or tripping) in this stage of sleep.

STAGE 1

The stage where sleep talking, sleep walking and night terrors may occur.

STAGE 4

The stage of sleep where dreaming occurs.

STAGE 5

N-REM stages of sleep.

STAGES 1-4