Nov 5, 2019
While you rest, your body goes through different stages of the sleep cycle. Deep sleep, for example, is the stage of sleep you need to feel refreshed when you wake up in the morning. Unlike rapid eye movement (REM) sleep, deep sleep is when your body and brain waves slow down.
It’s hard to wake from deep sleep, and if you do, you may feel particularly groggy.
Read on to learn more about this part of your sleep cycle.