Sleep. Why do we need it?

How long did you sleep last night? Do you remember what you dreamed about? How much sleep do you get on a daily basis? Do you feel tired throughout the day?  This blog will explore the psychological and biological answers to these questions.

Our bodies are like biological clocks.  Our clocks have two cycles, we have a 24 hour biological clock and a 90 minute sleep cycle.

Our biological clock is called circadian rhythm.  As the sun starts to rise our body temperature actually rises, then it peaks mid day,then it lowers in the afternoon which is why lots of people enjoy an afternoon nap, then it drops again in the evening.

Every 90 minutes, we go through a cycle of four different sleep stags.  One of these stages is called REM sleep (rapid eye movement.)  REM sleep is when you have your dreams.  So when I was being chosen for the hunger games and running from tornados, my eyes were closed, but frantically moving back and forth in my sleep.  If someone would have scanned my brain, the activity during dreaming would have looked like I was actually awake!

As you start to fall asleep at night, your brain is full of slow alpha waves; this is when you're really relaxed but still awake.  Next you slowly slip into the first sleep stage, non-REM sleep called NREM-1.  Do you know that feeling you get when you lay in bed and you swear you're falling? That happens during NREM-1; during this stage people often experience things that resemble hallucinations.

Next as you relax more deeply you fall into NREM-2 for about 20 minutes where your brain has random bursts of rapid rhythmic brain wave activity.  At this stage it would still be easy to wake you, but you're now falling into a deeper sleep.

After that you fall into NREM-3 for the next 30 minutes where your brain is now sending out large slow delta waves and you become very hard to be waken.  This is usually the stage when children may wet the bed.

One hour into sleep we enter REM sleep, the stage of rapid eye movement and dreaming. Your heart rate rises during this stage, your breathing quickens,  and your eyes dart back and forth about every 30 seconds behind your closed eyelids.  If someone is thrashing around during their sleep, they aren't in REM sleep.  During REM sleep, your body is practically paralyzed rather than the occasional finger twitch.  Your motor cortex is active during REM sleep, but your brainstem does not accept its messages, so your muscles stay relaxed and still.

So as you sleep you go through all of these cycles.  And fun fact! If you wake up and you remember your dream, it is most likely because you were woken up during REM sleep when you were having your dream.  And if you wake up thinking you didn't have a dream it is just because you woke up when you were in one of the other stages and you simply don't remember the dream.

You've heard people say "everyone needs 8 hours of sleep!" right? Well, it isn't true.  Our sleep patterns change a lot over our lives.  Newborns sleep 2/3 of their day while adults usually sleep less thank 1/3.  Sleep patterns are often linked to genetics, so some people may require 9 hours and others can go on just a few.

Have you ever wondered why we even need sleep? Why do we have to spend one to two thirds of our lives in this semi comatose state? Psychologists have five theories as to why sleep evolved as a necessity:

1. Sleep protects

2. Sleep helps us recuperate

3. Sleep helps restore and rebuild our fading memories of the day's experiences

4. Sleep feeds creative thinking

5. Sleep supports growth

We aren't the only beings that need sleep obviously; all living things need sleep and we all need it to different degrees. Here's a fun little list of how much sleep animals need from 20 hours to 2 hours.

Bats: 20 hours
Human infants: 16 hours
Cats: 12 hours
Dolphins: 10 hours
Human adults: 8 hours
Cows: 4 hours
Giraffes: 2 hours

So what happens when we aren't getting the amount of sleep that we need? How do we know if we aren't getting enough sleep? Here is a little test to see if you're getting enough sleep:

True or False
1. I need an alarm to wake up
2. Its a struggle for me to get out of bed in the morning
3. Weekday mornings i hot snooze several times
4. I feel tired, irritable and stressed during the week
5. I have trouble concentrating/remembering
6. I fall asleep watching TV
7. I feel slow with critical thinking, problem solving and being creative
8. I fall asleep in boring meetings/lectures/in warm rooms
9. I fall asleep after heavy meals/drinking alcohol
10. I fall asleep while relaxing after dinner
11. I fall asleep within 5 minutes of getting into bed
12. I often feel drowsy when driving
13. I often need a nap to get through the day
14. I often sleep extra hours on weekend mornings
15. I have dark circles under my eyes

Well... If you answered True to three or more of those...then chances are you aren't getting enough sleep!  One way to get the right amount of sleep is to go to bed 15 minutes earlier than usual each week until you wake up without an alarm and feel alert all day!

Have you ever had trouble going to sleep at night? You feel anxious or excited and you keep laying there unable to go to sleep? well then you're the 1 out of 10 adults that has insomnia.  As people get older it turns into 1 out of 4, so it's really quite common.   The opposite of insomnia is narcolepsy, where you fall asleep instantly with no control over it, and it usually happens when you're over excited.  Want to see something extremely adorable and incredibly sad? Watch this little narcoleptic puppy!

Only one out of 2000 people have narcolepsy so many more of us struggle with not sleeping than falling asleep too quickly.

A scarier sleep disorder is sleep apnea.  Apnea means "with no breath."  This was unknown until modern medicine, and during sleep apnea people can literally stop breathing momentarily while sleeping.  They don't die however, because the oxygen in their blood decreases so much that it arouses them and they wake up enough to snort in air loudly.  (So if you know anyone who sleeps like this, please tell them to get it checked out! There are machines you can use while sleeping that can help with this!)

I used to struggle with night terrors, but before today I thought it was called sleepwalking and that night terrors were nightmares, but I was wrong! Night terrors usually happen in children where they sit up and walk around and talk incoherently; there heart rates and breathing rates are usually doubled, and they appear terrified.

I hope I've helped to provide you with some insight about why and how you spend a third of your life sleeping!