Sleep Stages: What Happens During Sleep?

Dreaming, snoring, tossing and turning -- there are lots of things we do while we're sleeping, but what's actually going on while you're in the land of nod?

Research has come a long way in helping us understand that sleep is more than just a required period of inactivity for our bodies and brains. "Only in the last five to 10 years has research shown that sleep is biologically programmed into virtually every single cell of your body," Michael J. Twery, Ph.D., director of the National Center on Sleep Disorders Research (NCSDR) at the National Heart, Lung, and Blood Institute (NHLBI) tells The Huffington Post.

Sleep not only restores the body after a long day, it also seems to play a role in learning and memory, growth and development and immunity, yet researchers still don't know exactly why or how sleep works its many wonders.

We do know that these different functions seem to take place during different phases of the night, although there's no one "best" stage of sleep, Lawrence Epstein, M.D., chief medical officer of Sleep HealthCenters and co-author of "The Harvard Medical School's Guide to a Good Night's Sleep" tells The Huffington Post. "In order to get all the benefits of sleep you need to get adequate amounts of sleep."

The average adult needs seven to nine hours a night, but ideally you should sleep until you wake up naturally. "If you're waking someone up from sleep, it means they haven't slept enough," says Dr. Epstein. So, that alarm clock screaming that it's time to get going? "I think it's the best way to sleep deprive yourself," he says.

In order to better understand what sleep does for your body and brain, here's a look at what's happening as you transition from going about your day to hitting the hay.

Comments

[ms.understood]

05:38 AM on 03/03/2012

i am absolutely not a morning person. i wonder if sleep inertia plays a part in that?

[FinalHorcrux]

10:12 AM on 02/29/2012

I thought this article was good until it said to wake up naturally. Wow, if I did that then I'd never be able to get to school. Thanks for that tip, it was very helpful. *side eye*

[Brett Tonaille]

11:36 PM on 02/29/2012

But of course the trick is to go to bed early enough that you CAN wake up early enough to get to school - or, one day, work.
Whether or not you manage to do it, there's no doubt it's the best thing to do.

[wakeboardwonder]

09:36 AM on 02/29/2012

What a cool article! I am always on the lookout for more information on sleep, particularly dreaming. I have started experiencing sleep paralysis in recent years and while its only happened a couple times, it can be really disturbing. I can see how some people think they are being abducted by aliens! lol Its nice to have answers when crazy stuff like that happens.

[UKNY]

09:40 AM on 03/02/2012

Sleep paralysis is the gateway to astral projection. Look it up, it's fascinating. I haven't reached a point at which I'm comfortable projecting voluntarily but my brothers do it regularly and happily.

[nokiahmtorz]

09:26 PM on 02/28/2012

If there is anyone who doubts this article; do this:
try waking up every morning for 1 week (at least) in a row on only three hours of sleep per night. Then try going about your normal school/work day. Then come back and tell me this article is a bunch of lies...I mean, honestly... This doctor is simply expounding on what we know, or at least should know.

[oilmlh]

02:22 PM on 02/28/2012

B. S. get your butt out of bed and go to work.

[lensamy]

01:46 PM on 02/28/2012

I dont think we will never be able to fully understand how the brain really works let alone the science of sleep. For whatever reason sometimes im having a dream the wake up use the bathroom or whatever and when i fall asleep again either i dream the same dream or resume the dream and finish whatever i was doing in the dream. Very peculiar i wonder if theres a name for that?.

[slister45]

01:43 PM on 02/28/2012

Why do we have to watch a commercial in order to watch at 54 second video?

[happyjoyjoy333]

12:48 PM on 02/28/2012

I remember most of my dreams, sometimes 5 or 6 a night, usually just the last few closest to awakening. My dreams can introduce themselves into my waking hours at anytime. It feels like the door between "here" and "there" is left ajar. I remember dreams back to childhood, about 50+ years. When remembering a dream, dozens of others come cascading after it, as if by plucking one orange from the stand, the rest tumble down to the floor. The dreams seem to be held in a "library", because when I remember one dream, the rest that follow are in the same genre. (flying, crossing an ocean, traveling through space, childhood, siblings, aliens, etc.) They seem to be categorized by main topics/places. They flash at lightning speed through my mind, and just a glimpse of them imparts the entire dream content at once. I compare it to the experience of my life flashing before my eyes. Every detail is there at once.
None are scary, even ones most people would consider nightmarish. I have seen my own corpse in a dream many times. I'mdifferent ages in my dreams. I can be an old black woman or a white kid in kindergarten. I know when the information imparted to me in my dreams comes from myself, others, angels, or God. I have met evil personified face-to-face in my dreams and not even been afraid.
Anyone else have the ability to remember all their dreams too?

[Still kickin]

12:45 PM on 02/28/2012

So I guess getting up to pee ever 90-120 minutes is probably not doing me much good. Although the alternative would be nastier....

[greenfinpopfish2]

11:38 AM on 02/28/2012

Last night I had a dream that I was eating a giant marshmellow .... I woke up and half my pillow was gone!

[michaelnel4449]

10:38 AM on 02/28/2012

We should sleep until we wake up, now that's a good one. We should also have a functioning government, electric cars, solar and geothermol powerstations, no poverty or starvation as well. Seems in a perfect world we could have it all, let's get started people and make it happen...

[keramos]

12:18 PM on 02/28/2012

Can we start with the sleep part first?

[MartinGillespie]

10:26 AM on 02/28/2012

This article made me want to go to sleep.

[happyjoyjoy333]

01:09 PM on 02/28/2012

:o)
I am in favor of ALL employers being mandated to let their employees take one nap per shift. My very best slepp happens when I nap. Often a one hour nap is better than 10 hours of regular sleep.

[one1byke]

07:24 AM on 02/28/2012

.... just here for the Russian spy lady in Red... but... then I got to thinking.

"the muscles are still unable to move"

I used to be able to - or, at least, - this happened to me pretty often.
I always thought, that if I didn't start moving, and went back into unconsciousness, I would die.
I never went back to sleep. I would concentrate on moving one limb until I snapped out of it.
It's one of the strangest feelings... our window into the realities of a quadriplegia.

[csaltman1]

11:04 AM on 02/28/2012

Check out sleep paralysis stories, hypnagogic dreams. Often, people will be paralyzed and sense an evil presence in the room with them, this is common of the experience. People have based superstitions on this, from succubi, to alien abduction. There's a reason the vast majority of ghost sightings happen when people are lying down or in bed, due to this.

[dwagner948]

12:01 PM on 02/28/2012

you've had sleep paralysis. One of the many curious features of REM sleep is that our skeletal muscles are paralyzed during it, a phenomenon known as REM atonia. Meanwhile, the cerebral cortex is highly active; REM is when we do most of our dreaming. Both of these features of REM are generated by signals from various nuclei in the pons, the middle section of the brain stem. In sleep paralysis the pons --> cortex pathways switch into wakefulness but the pons --> spinal motor neurons pathway stays in the REM mode, producing an awake brain in a paralyzed body. It's a frightening but entirely benign phenomenon which occurs once or twice in the lives of about 20% of people, usually in adolescence. Sleep deprivation seems to increase the risk of having it. It also occurs as an isolated symptom/disorder that runs in families, and as one of the 4 cardinal symptoms of narcolepsy-cataplexy syndrome.

A sleep doctor

[wakeboardwonder]

09:45 AM on 02/29/2012

Great comment dwagner948! Thank you!! The first time I experienced sleep paralysis I was 21. It has happened about 10 times since and I am now 24. Interestingly enough, there usually seems to be 2 or 3 'people' in the room with me when this happens. The second time it ever happened to me 3 'people' were in the room. I only felt threatened by one of them and have never felt threated or scared since. Usually I just want to be able to move so I can see them clearly. It is ssooo weird. Doesn't run in my family to my knowledge and I'm far from sleep deprived. Its strange.

[bhamnikwa]

06:39 AM on 02/28/2012

"If you're waking someone up from sleep, it means they haven't slept enough," says Dr. Epstein.

Now that has got to be one smart doctor.
The next person that wakes me up, I'm suing.

[jmoser1973]

07:36 AM on 02/28/2012

lol that was the one thing that stuck out for me.

[bhamnikwa]

07:50 AM on 02/28/2012

There are just some things even a PHD shouldn't say.

[csaltman1]

11:05 AM on 02/28/2012

He is saying it's unhealthy to use an alarm clock to wake up or to be woken up by anything other than your own self naturally waking after you've slept long enough. This is hardly something everyone already knows.

[Michelle Teresa Lopez]

11:28 AM on 02/28/2012

Really? It seems pretty common sense to me. If you are still tired, your body is going to keep you in sleep mode. If you have had enough sleep, you usually wake up. I am fortunate that I work in the afternoon/evening so I wake up naturally every day, pretty much.

[bhamnikwa]

08:47 PM on 02/28/2012

I realize what he was saying. And my point was that this is something known as common sense. Not that he was stupid for saying it.
There are a lot of people out there that don't have or use common sense, so maybe they would need to be told this. Thanks for the reply though.

[thegrrrr8est]

10:17 PM on 02/27/2012

Really interesting article, but the artifice of breaking it up so that one has to click through pointless photos took a lot of the luster off of it.

Now, having groused, I'll ask this...I've dreamed "musicals" in which all communication was sung; I've dreamed "posting" dreams in which everything was typed as in a message like this; I've even dreamed in foreign languages. Darned if I understand why any of that happened.

[happyjoyjoy333]

01:05 PM on 02/28/2012

It sounds like you may be proof of Jung's "collective unconcious".
Often I have entertained that the human concious is connected ....ala: fish school, birds flock, horses herd, and people "mob". In fact, people in mobs will commit horrendous acts of violence that in normal circumstances they would be unable to commit.....similar to a "feeding frenzy" where living creatures are swept up by unseen instincts. creatures in a "feeding frenzy" have been known to tear each other apart in the process. That alone testifies to a pretty strong unseen force motivating them.... something not in their concious control.
The thought of humanity having a "collective concious" gives rise to the parallel idea that maybe we have a "collective UNconcious" too.
It would explain a lot.
#1. No one commits a murder, without the hidden consent of us all.

[thegrrrr8est]

03:01 PM on 02/28/2012

Whoa! I'm hoping the collective unconscious is also capable of mob activity of healing, creating peace and joy and growing out of our baser natures.

I do give great credence to the concept of a collective unconscious. There's just too much coming and going in our minds to be the product or a single wrinkled little brain.

Thanks for your response. Sounds to me like you'd be fascinating dinner company.