# sleeping and erections. **URL:** \ **Category:** Factual Questions\ **Created:** [October 11, 2011, 5:09am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265 "2011-10-11T05:09:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![copperwindow](https://avatars.discourse-cdn.com/v4/letter/c/4af34b/32.png) [@copperwindow](https://boards.straightdope.com/u/copperwindow)\ **Post date:** [October 11, 2011, 5:09am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/1 "2011-10-11T05:09:54Z")
Why does my penis become erect when I fall asleep? ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [October 11, 2011, 5:17am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/2 "2011-10-11T05:17:38Z")
How do you know? Isn’t it more likely it happens when you start to wake up again? ---
**Author:** ![Indian](https://avatars.discourse-cdn.com/v4/letter/i/c0e974/32.png) [@Indian](https://boards.straightdope.com/u/Indian)\ **Post date:** [October 11, 2011, 5:57am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/3 "2011-10-11T05:57:34Z")
You may try peeing before you go to sleep. ---
**Author:** ![scootergirl](https://avatars.discourse-cdn.com/v4/letter/s/e99b99/32.png) [@scootergirl](https://boards.straightdope.com/u/scootergirl)\ **Post date:** [October 11, 2011, 6:06am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/4 "2011-10-11T06:06:16Z")
Because you are dreaming about sex. Duh! Actually, not having one I cannot say I’m an expert in this, but I do remember reading a while back that erections during sleep happen during REM, when one is most relaxed. Which means that you could be having multiple erections while you sleep. I know! Set up a camera and conduct your own study!😃 ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [October 11, 2011, 6:53am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/5 "2011-10-11T06:53:38Z")
It’s much more common to have an erection when you awaken. Perhaps your subconscious is anticipating this. Or, it might have something to do with the relinquishing of control as you fall asleep. ---
**Author:** ![studmuffin](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@studmuffin](https://boards.straightdope.com/u/studmuffin)\ **Post date:** [October 11, 2011, 11:54am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/6 "2011-10-11T11:54:13Z")
For some reason unknown a full bladder can instigate an unwanted erection, the pleasure receptors can’t tell the difference between genuine sexual stimuli and the need to wee-wee which just shows that the human brain is not as smart as we are led to believe. Also sleeping in the buffo doesn’t help, friction with the sheets causes the brain to inflate the trouser snake. Hell’s teeth, when it comes to sex the human brain doesn’t cope well. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [October 11, 2011, 11:57am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/7 "2011-10-11T11:57:53Z")
Report! Stimulus unknown. Proceed to default subroutine. Inflating trouser snake. ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [October 11, 2011, 12:33pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/8 "2011-10-11T12:33:50Z")
It’s your bodies way of keeping you from rolling over. Like a built-in kick stand. ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [October 11, 2011, 12:35pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/9 "2011-10-11T12:35:53Z")
No, no, no, no, no. [Erections are a normal part of REM sleep](http://en.wikipedia.org/wiki/Rapid_eye_movement_sleep#Physiology) (see second paragraph), so much so that a lack of them is a way of diagnosing erectile dysfunction (look up “[postage stamp test](http://www.nlm.nih.gov/medlineplus/ency/article/003339.htm)”). It has nothing to do with a full bladder, and is present in any dreams, erotic or otherwise. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [October 11, 2011, 1:43pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/10 "2011-10-11T13:43:13Z")
> [@RealityChuck](#): > > No, no, no, no, no. > > [Erections are a normal part of REM sleep](http://en.wikipedia.org/wiki/Rapid_eye_movement_sleep#Physiology) (see second paragraph), so much so that a lack of them is a way of diagnosing erectile dysfunction (look up “[postage stamp test](http://www.nlm.nih.gov/medlineplus/ency/article/003339.htm)”)… Hmm. Has the Postmaster General approved that test? ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [October 11, 2011, 9:52pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/11 "2011-10-11T21:52:24Z")
> [@Elendil\_s\_Heir](#): > > Hmm. Has the Postmaster General approved that test? And how could it work with self-adhesive stamps? Like nearly all of the stamps used in the USA now. ---
**Author:** ![Happy\_Lendervedder](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/happy_lendervedder/32/8488_2.png) [@Happy\_Lendervedder](https://boards.straightdope.com/u/Happy_Lendervedder)\ **Post date:** [October 11, 2011, 10:00pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/12 "2011-10-11T22:00:04Z")
> [@Elendil\_s\_Heir](#): > > Hmm. Has the Postmaster General approved that test? I don’t know, but maybe this is the big break the USPS has been looking for. ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [October 11, 2011, 11:29pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/13 "2011-10-11T23:29:48Z")
> [@RealityChuck](#): > > No, no, no, no, no. > > [Erections are a normal part of REM sleep](http://en.wikipedia.org/wiki/Rapid_eye_movement_sleep#Physiology) (see second paragraph), so much so that a lack of them is a way of diagnosing erectile dysfunction (look up “[postage stamp test](http://www.nlm.nih.gov/medlineplus/ency/article/003339.htm)”). > > It has nothing to do with a full bladder, and is present in any dreams, erotic or otherwise. The specifics of this test are moronic. Why do you have to put your penis through the fly, apply the stamps and then put the penis back through the fly? Why not just drop your shorts, apply the stamps, and then pull up your shorts and arrange your penis appropriately? Anyway, when I wake up due to having to pee, I often have at least a semi-erection. I have always assumed that this is because, before waking up, I have been unconsciously clenching my sphincter so as to avoid wetting the bed, thereby inducing the semi-erection. I don’t know what happens during REM sleep, since I’m, well, asleep. Roddy ---
**Author:** ![fubbleskag](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@fubbleskag](https://boards.straightdope.com/u/fubbleskag)\ **Post date:** [October 12, 2011, 12:07am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/14 "2011-10-12T00:07:10Z")
IANAD, but I’ve always assumed that the mid-night and/or morning erection is to prevent me from peeing the bed (ever tried to pee with an erection?) which would explain why children and the elderly are more likely to suffer incontinence. ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [October 12, 2011, 12:51am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/15 "2011-10-12T00:51:59Z")
> [@fubbleskag](#): > > IANAD, but I’ve always assumed that the mid-night and/or morning erection is to prevent me from peeing the bed (ever tried to pee with an erection?) which would explain why children and the elderly are more likely to suffer incontinence. 😕 Are male children less likely than male adults to get involuntary or reflex erections, e.g., while sleeping? I know that pre-pubescent boys don’t have the hormonal development to ejaculate, but I thought they could have non-sexual erections just like the grown-ups. IANA male, so I have no personal experience in this matter. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [October 12, 2011, 12:58am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/16 "2011-10-12T00:58:18Z")
> [@fubbleskag](#): > > IANAD, but I’ve always assumed that the mid-night and/or morning erection is to prevent me from peeing the bed (ever tried to pee with an erection?) which would explain why children and the elderly are more likely to suffer incontinence. I don’t think I’m unusual in this… As a kid - even at an age when I had no clue what an erection was for - I woke up with one about as often as I do in adulthood. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [October 12, 2011, 2:39am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/17 "2011-10-12T02:39:42Z")
> [@Happy\_Lendervedder](#): > > I don’t know, but maybe this is the big break the USPS has been looking for. Heheheh. I want to find a really beautiful postal clerk and ask for a hand cancellation. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 12, 2011, 3:49am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/18 "2011-10-12T03:49:32Z")
The morning wood because of full bladder story just won’t die, will it? The true story is that both have a common cause: You were sleeping. You get an erection because you’re asleep, and you have to pee because you haven’t peed for eight hours. ---
**Author:** ![from\_a\_to\_z](https://avatars.discourse-cdn.com/v4/letter/f/5fc32e/32.png) [@from\_a\_to\_z](https://boards.straightdope.com/u/from_a_to_z)\ **Post date:** [October 12, 2011, 5:06am UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/19 "2011-10-12T05:06:37Z")
Is there a specific strip of postage stamps that is more appropriate, like “Dogwood Blossoms - Please Join Us”? Anyway, speaking of post #1, per the 2009 book _The Scientific American Day in the Life of Your Brain_, pages 151-152 [http://books.google.com/books?id=25BkVww7uTIC&pg=PA151&lpg=PA151&dq=%22Scientific+American%22+penis+erection&source=bl&ots=DPgP5S1am6&sig=h1lrcIipYOD0EhmncoiI7pXIj4c&hl=en&ei=BhiVTs2nIOLWiAKx1cntAg&sa=X&oi=book\_result&ct=result&resnum=5&ved=0CFUQ6AEwBA#v=onepage&q&f=false](http://books.google.com/books?id=25BkVww7uTIC&pg=PA151&lpg=PA151&dq=%22Scientific+American%22+penis+erection&source=bl&ots=DPgP5S1am6&sig=h1lrcIipYOD0EhmncoiI7pXIj4c&hl=en&ei=BhiVTs2nIOLWiAKx1cntAg&sa=X&oi=book_result&ct=result&resnum=5&ved=0CFUQ6AEwBA#v=onepage&q&f=false): > [@](#): > > An erect penis appears to be the default state. One of the important functions of the brain is to suppress erections most of the time, so that men can go about other business and also protect the blood vessels from damage from being constantly engorged. I do wonder how much time the author Judith Horstman spent looking. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [October 12, 2011, 12:45pm UTC](https://boards.straightdope.com/t/sleeping-and-erections/599265/20 "2011-10-12T12:45:39Z")
> [@Chronos](#): > > The morning wood because of full bladder story just won’t die, will it? The true story is that both have a common cause: You were sleeping. You get an erection because you’re asleep, and you have to pee because you haven’t peed for eight hours. It won’t die because, as far as I know, no test has been done to prove that there is no connection. So we rely on anecdotes. slightly TMI: I know that, every time I’ve had a post awakening erection, I’ve needed to pee around 16 oz or so, but I when I don’t need to pee much, my penis is always flaccid. I also know that I’ve woken many times during REM sleep without an erection, and I am very clearly not impotent. Maybe it’s all a cognitive bias. But, without a study, I trust my observations. Though now I know that there is not supposed to be a connection, I’ll pay even more attention. [Next page](https://boards.straightdope.com/t/sleeping-and-erections/599265.md?page=2)