Waking up in the morning next to last night’s joy, I noticed that he had gotten hard again. We were contemplating this, and it occured to us to ask why it happens.
I couldn’t remember the answer, if I’d ever known it, and neither could he. On searching the archives here, I didn’t find it. So I’m asking. smile
Why do men get hard first thing in the morning, regardless of dreams or mood or anything (seemingly) else?
-Elthia
Short answer: Sheer hydraulic pressure.
Longer answer (no pun intended): In deference to Uncle Beer’s request to avoid TMI-like threat content, let’s just say that the kind of things that guys do (subconsciously) to avoid peeing are the same things they do to enhance… certain responses…
I search the archives and GQ but didn’t find a definitive answer.
Bladder pressure by itself isn’t enough. If I drink a lot of water during the day and get a very full bladder, I do not get an erection. I believe that morning is when a man’s testosterone peaks. This is probably the main factor. Nitric oxide is also a factor in erection. WAG: maybe this just accumulates in the body overnight due to reduced respiration.
People have many dreams and thoughts every night. Even when you dont remember your dreams, you are still having them. And even when you remember your dreams, you still have some that same night that you dont remember. I am pretty sure these subconscious, unremembered dreams have something to do with it.
Do a search on “morning woody.” The TM love talking about this.
I’m sure I read some while ago that it’s not really a morning function, that just happens to be when we are aware of it. IIRC, your average guy has this happen half-a-dozen times during an average nights sleep.
Kind of the wrong way round if you ask me butI guess it is less embarrassing
Male have many erections while they sleep. The reason is because erections are caused by the parasympathetic nervous system, which is beyond conscious control. However, when we are conscious our brain is working to inhibit erections. When we are asleep our parasympatheic nervous system has free reign to cause as many erections as it can. So, since many men have an erection for a good percentage of the night, many men also wake up with one.
Then how come, back in high school, i would get an erection on the morning ride on the school bus AFTER i woke up. sometimes i get my “morning wood” up to a half an hour after i wake up.
do you know the definition of torque?
its when you get up in the morning and its rock hard and you go to pee and bend it down towards the toilet and your heels come off the ground. thats torque.
Its a barometer.
If its hard it will be sunny and clear, if it is soft then I wake up the wife and say to her “Uh-Oh. Looks like rain. If you want the car washed and the lawn mowed, the gutters cleaned and the leaves rakes, you better make the sun shine!”
Works like a charm 
[Butthead]
Sometimes I get morning wood in the late afternoon.
[/Butthead]
Anecdotally: This autonomic function occurs even in infant boys. I’ve heard of mothers startled at what they find when they change Junior’s diaper.
Not for asking the question, but for not knowing the answer.
The condition you speak of is the male body’s critical defense against damage to this rather highly prized appendage.
Have you ever woken up after sleeping with your ear folded under your head? Did you notice how painful this was? Now, imagine kinking your penis while you are asleep.
Prolonged obstruction of blood flow in the penile member could easily result in permanent damage to the erectile tissues of said organ. Periodic, spontaneous erections during the course of a night’s sleep is an excellent way of preventing this.
It is safe to assume that early menfolk without this vital autonomic response were weeded out of the geen pool rather quickly. A non-functional sexual appendage is a surefire ticket to extinction.
So much for my “just horny” theory.
Exactly.
Ever notice that the abandoned jail in The Simpsons is called Morningwood Penitentiary? (Gimme a break, where else could I post this!)
Let’s see;
Sexually perverted reference… Check!
Mention of The Simpsons… Check!
Use of irony while commiting a SDMB post… Check!
You’ll fit in just fine around here. Keep up (as it were) the good work!
posted by eunoia
Naturally. After all, it’s part of the penile system, isn’t it?
Damn, that used to be embarrassing. I thought it was triggered by the vibration of the bus (don’t get me started on motorbikes…) but, looking back, I tend to think it was just general horniness.
However, on matters of horniness and auto-motives perhaps we’d do better to consult with that old SDMB favourite…
Dick Trickle - we need to get this guy on the SD Science Advisory Board
Men, on average, have a sexual thought every…10 seconds is it? Well, when you’re asleep, you (men) still have those thoughts, but when you’re asleep, its a little difficult to control your ‘John Thomas’ and sometimes those thoughts come to your head right before you wake and there it is… Thats what I heard anyway. It makes sense…doesn’t it?