stages of sleep

Why is Sleep Important?

Did you know that your body does a lot more than simply relax during sleep? Well, some of your body’s most productive work is done while you’re sleeping!

What is Sleep?

Sleeping is your body’s way of recuperating the energy used each day by your mental and physical activity. Neurotransmitters signal parts of the your brain that its time to rest.

There are two basic types, rapid eye movement (REM) and non-REM. Overall, sleep has 4 stages, and non-REM has three stages on its own…

stages of sleep

Stage 1 (non-REM)

This stage is the shift from being awke to sleeping. This short time period, lasting several minutes, many things happen throughout the body to prepare it for the rest of the cycle:

  • Sleep is “light”
  • Heartbeat slows
  • Breathing lessens
  • Eye movements slow
  • Your brain waves decrease from daytime levels

Stage 2 (non-REM)

This stage is the last before you enter deeper sleep.

  • Heartbeat and breathing decrease more
  • Muscles relax even further
  • Your body temperature drops
  • Eye movements stop
  • Slow brain activity is interrupted by short bursts of activity
  • Your body spends the most time in this stage

Stage 3 (non-REM)

Stage 3 is the deep sleep that you require to feel refreshed in the mornings.

  • Occurs in longer periods during the first half of the night
  • Heartbeat and breathing slow to their lowest levels
  • Muscles are most relaxed
  • Brain waves are slowest
  • You are most difficult to wake up during this stage

REM sleep

This is the most “active” stage of sleep. It first occurs around 90 minutes after falling asleep.

  • Dreaming happens during this stage
  • Eyes move rapidly behind eyelids
  • Brain waves are close to the level of being awake
  • Breathing is fast and irregular
  • Heart rate and blood pressure increase
  • Arm and leg muscles become temporarily paralyzed (preventing you from acting out any dreams)

A complete sleep cycle (all 4 stages) takes between 90-110 minutes. Each cycle sees a longer period of REM sleep, the longest being the final sleep cycle before you wake up.

How much sleep do you need

How Much Sleep do I Need?

This answer is very open-ended. There is no magic number of hours that your should be getting per night, every person is different. Babies generally nap as much as 16-20 hours per day. That has much to do with the rapid development of their body’s and brains. Children of school age and teenagers usually sleep as much as 9.5 hours per night. Again, this depends on the person or child in question. Adults sleep anywhere between 6-9 hours, redundantly, this again depends on the person.

Once you reach the age of 60 you tend to begin sleeping less and less. As your body gets into the later stages of life you tend to use less energy, therefore, requiring less recuperation of energy. Additionally, people of that age will more likely use medications that affect sleeping habits.

Overall, people are sleeping less than they need due to long work hours and the vast availability of screen-related entertainment.

NOTE: The theory that you can “catch up” on sleeping during the weekends is not always worthwhile. Keeping a steady schedule is really best for your system. Now, not to say that you can’t sleep in a bit on the weekends. However, if you wake up at 5am and go to bed at 10pm during the work week, it is not advised for you to stay awake till 2am and sleep till noon every weekend.

The Power of Sleep

Memory Improvement

Proper sleep ensures your short-term memory is processed into long-term memory. The process, called consolidation, improves your overall cognition. The following functions are all involved:

  • Creativity
  • Language use
  • Reasoning
  • Knowledge retention
  • Thinking capacity
  • Attention
  • Judgement
  • Problem solving


The seemingly never-ending cycle of depression is likely fueled by a lack of proper sleep. If you’re losing sleep due to long work hours, stress, medication, etc. then the lack of rest is just going to amplify those minor issues. Some research leans towards things like anxiety, depression and stress are caused by poor sleep, rather than the opposite.

Growth & Development

Sleeping releases a growth hormone in children. Lack of proper sleep will negatively affect the growth of your children, leading to countless complications throughout their lives.

What Happens to Your Body Without Any Sleep?

lack of sleepNow, this may only apply to .1% of the people who come across this blog, but its interesting nonetheless. Your body begins showing signs of destruction after just one full day without rest.

24 Hours

Most of us have pulled the well known “all-nighter” at some point during our lives, whether it was for a party, a study binge, or a sick child. Also, we all know that you feel awful until you get some shut-eye.

“When you’ve gone 24 hours without even a nap, you’re not going to be able to think as clearly. In fact, your brain will work the same as someone with a blood alcohol content of .10, which is above the legal limit to be convicted of a DUI in all 50 US states.” -(Can we Survive Without Sleeping?)

You will have issues with memory, hand-eye coordination, hearing and judgement.

36 Hours

Multiple stints of this length without sleeping will lead to cardiovascular disease, high blood pressure and chemical imbalances. Additionally, you will experience complete memory loss of certain portions of the day.

48 Hours

After two days of no sleep, your body will begin forcing you to nap by way of “microsleeps.” Don’t confuse these with a catnap…they are periodical blackouts that you won’t be able to control. The issues mentioned at 24 & 36 hours will get worse, as well!

72 Hours

Three days without rest is where the inconclusive results lie. As with any ailment, your overall health and genealogy will ultimately determine how your body handles the situation. You’ll begin to have hallucinations, and simply speaking will seem like a trigonometry exam.

Accurate studies have not been tested extensively going more than 3 days without sleep. Although, we can’t imagine that your body would last much longer after this…organs will shut down, your nervous system will fail you, ultimately leading to your demise.

*Sleeping is just as crucial as food and water for your body! Take your rest seriously, and see a doctor if you feel that you are not getting enough of it!


  • Admin. “Amazing Reasons to Have Proper Sleep.” PositiveViewZ, 1 Sept. 2017,
  • “Brain Basics: Understanding Sleep.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services, 2018,
  • “Is Lack of Sleep Affecting Your Lifestyle?” Mattress World Northwest, 19 Jan. 2018,
  • Kittredge, Clare. “How Much Sleep Do You Need? | Everyday Health.” Stroke Center –, Everyday Health, 25 Jan. 2018,
  • Reddick, Mark. “How Long Can You Survive Without Sleep? What Happens to Your Body?” The Sleep Advisor, 5 June 2018,
  • Schocker, Laura. “Your Body Does Incredible Things When You Aren’t Awake.” The Huffington Post,, 7 Dec. 2017,

About the Author


Jason Smith is recognized by the board of polysomnographic technologists (BRPT) as a registered polysomnographic technologist (RPSGT) since 2003. He is also Director of Clinical Operations for 6 multi-state sleep diagnostic facilities including the nation’s largest 20 bed sleep disorder testing center. Jason has also been a Co-Author with two research publications featured in Journal of Clinical Sleep Medicine.