Stages of Sleep
Sleeping is a complex process with 4 different stages that make up a sleep cycle.
When we first fall asleep we enter non-rapid eye movement sleep (NREM). This is divided into three stages, with each becoming progressively deeper.
Stage 1 and 2 are light phases of sleep, from which we can be easily roused.
Stage 3 becomes deeper, and if woken up, we can feel disorientated.
Stage 4 is known as rapid eye movement sleep (REM), the stage at which we dream.
Each sleep cycle lasts around one and a half hours, and in order to feel fully rested and refreshed when we wake up, we must experience all four stages. A full night’s sleep will include of five or six cycles, while a disturbed, restless night consists of fewer.