By: Samantha deCastro

Today we are going to go through the stages of sleep.
These stages are generally broken down into REM (or Rapid Eye Movement) and non-REM sleep. Firstly, we will discuss non-REM, as that is where sleep starts.

Stage 1: This stage can last about 5-10 minutes. You've closed your eyes, but it is pretty easy to wake up. You may also some muscle twitching.

Stage 2: Light sleep, your heart rate is slowing down and your body temperature is dropping. Basically you’re starting to prepare for the big stuff, the deep sleep.

Stage 3: You have arrived at deep sleep. Congratulations. This is the stage where it is generally harder to be woken up, and if you are, you feel out of it for a few minutes. This is the stage where cool stuff like tissue repair happens, building up muscle and bone goes down and you immune system gets a boost.

Stage 4 or REM: This usually happens about 90 minutes in to your cycle and can last up to 10 minutes in your first sleep cycle, but gets longer and can be up to an hour later on in your sleep. Your brain is more active, your heart rate and breathing increases and this is usually when you can have some pretty intense dreams.

It is called REM because that is exactly what is happening. Your eyes are rapidly moving side to side under those eyelids. Your muscles are also essentially paralyzed by your brain stem, so you don’t act out your dreams in this deep state.

You cycle through these 4 stages multiple times a night.