Many people will deal with a sleeping problem at some point in their life.

There are over 80 types of sleep disorders. Some sleep disorders happen during or are worse during one or more stages of sleep. Knowing about the stages of sleep can help you understand what healthy sleep looks like.

Non-rapid eye movement (NREM) sleep

There are 3 stages of NREM sleep:

• Stage N1 happens right after you fall asleep. It is very short, usually less than 10 minutes. It involves light sleep from which you can be awakened easily.
• Stage N2 lasts about 30 to 60 minutes. During this stage, your muscles become more relaxed. This deeper stage of NREM may help your body recover.
• Stage N3 is a very deep sleep. It lasts about 20 to 40 minutes. During this stage, you may have some body movements. Your body also releases important hormones that control growth and healing. This helps your body restore and recover. 

Rapid eye movement (REM) sleep

REM sleep is also called the dream stage. It helps your brain in important ways. During REM sleep:

• your eyes move very fast (which gives REM sleep its name)
• you lose muscle tone (the tightness or stiffness of your muscles) and muscle power
• typically, only your breathing and eye muscles move

For most people, REM sleep happens every 90 minutes throughout the night.

• The first REM period may only last 5 minutes.
• The second REM period lasts about 10 minutes.
• The third REM period lasts about 15 minutes.
• The last REM period is about 30 to 60 minutes.

You may or may not remember dreaming during REM stages, but everyone dreams.     

What does healthy sleep look like?

You move through all of these stages several times during sleep. The stages don’t always happen in the same order or for the same amount of time. It’s important to get enough sleep so that all of the different stages of sleep can work together to keep you healthy.