The Sleep Phases

Sleep is made up of successive phases that follow a set of pattern. When we fall asleep, our brain waves gradually slow down.  This state lasts between 2 and 30 minutes, according to the individual.  We then fall into a phase of light sleep during which our body relaxes.  A slow sleep phase follows which gives way after around 20 minutes to deep sleep and then very deep or profound sleep.

Then comes the paradoxical phase, during which brain activity is just as important as it is during waking hours despite the fact that the body is totally inert except forREM (Rapid Eye Movement).  It is during this phase that we dream.

The cycle lasts between one and a half to two hours.  We then wake up for a few seconds, falling straight back to sleep before a new cycle begins, without having the least awareness of this process.