It’s a mystery as to why we sleep.

Researchers know it is a complex phenomenon and we now also know that it is critical to health. Sleep is a recipe of hormones and chemicals that create rhythms to drowsiness and wakefulness, a complicated dance of signals from the body combined with the clock.  

New technologies and monitoring systems are allowing us to learn more than ever before what happens when we slumber and how it impacts our times of being awake. And one thing research has shown over the years is that there are phases and stages to sleep. Although it may sometimes feel like it, we don’t dream all night; as a matter of fact, a dream state is a much shorter timeframe than you might think. Each of these stages cycles throughout the night, which is why you have times of deeper sleep and times where you feel closer to the surface. A typical cycle of sleep, comprised of all four stages, usually lasts between 70-120 minutes, before starting over again.

Take a look at the following identified stages of sleep and how long they typically last for a window into the secret world of sleep. 


This is a non-rapid eye movement stage of sleep as are the following two stages. Stage 1 is when you are beginning to fall asleep and usually lasts from 1 to 5 minutes. 


Stage 2 moves you into a deeper form of sleep, but you are still relatively easy to wake at this stage. Again, rapid eye movement (REM) is not part of this stage. This stage can last 10-60 minutes per cycle.


This stage of sleep is extremely important. Brain activity slows, your muscles relax. This is considered the deepest level of sleep while still non-REM. You typically enter this level of sleep for 20 to 40 minutes and is very important for brain health and body rejuvenation.


Stage 4 is where REM sleep occurs and is most familiar as the stage of sleep for dreaming. Usually lasting 10-60 minutes per cycle, your brain activity and breathing increase as you take fantastical adventures and process interactions, all within the confines of the mind. However, contrary to what is widely believed, this is not the only stage of sleep in which dreams can take place. Dreaming can also occur in the other stages of sleep, but is generally more vivid and intense during this stage. What is most significant about REM Stage 4 sleep is that it is considered essential for brain health, as it seems to impact brain health in areas like memory and learning. 

Each of these stages of sleep plays an important role in what is known as your overall sleep architecture. Understanding more about these stages can help you see how your body functions and benefits from sleep in all of its stages and cycles.