The 4 Stages of Sleep And What Happens in Each

Throughout the night, your body cycles through four stages of sleep. During these stages, your body’s brain waves, eye movements, and neurological activity varies. Together, the four stages last for about 90 minutes and your body cycles through these stages roughly four to six times per night.
The four stages include two main phases: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep. NREM is divided up into three sub-categories (N1, N2, and N3 sleep), bringing the total number of stages of sleep to four.
Keep reading to find out what happens in the brain and body during each stage of sleep, along with what factors tend to impact how well you sleep in each stage.
The 4 Stages of Sleep And What Happens in Each