Science Explains Why Men Get Erections In The Morning

It might seem funny to the female folks but it is highly embarrassing to the male folks all over the world. It is something every male has to deal with on a regular basis. What does science have to say about the unnecessary attention (pun intended) you receive every morning. Lets find out...


Morning Wood, or nocturnal penile tumescence (NPT) as they are correctly called, are spontaneous erections that occur during sleep or while waking up. Every man (no, you are not alone) without erectile dysfunction are graced with them and they normally occur around three to five times during sleep.

NPT actually starts in utero, or in the womb (seriously), and continues throughout life. If it’s any consolation, men aren’t completely alone—women also get clitoral erections and womanly engorgement during sleep, and various nonhuman mammals also get NPT.

While a few different theories have been proposed over the years to explain NPT, what causes it still remains uncertain.

NPT, just like clitoral erections, is associated with REM(rapid eye movement) sleep. They usually pop up (pun intended) during periods of Rapid Eye Movement (REM) sleep (when most dreaming occurs) and last around 30 minutes each. Unrelated to dream content, they are both common and completely normal and men older than sixty years may even have them during non-REM sleep.

While in REM sleep, your body turns off some neurotransmitters to regulate body functions. And one of those neurotransmitters, Norepinephrine, is the one in charge of stopping erections. Basically, when REM decreases the Norepinephrine levels, testosterone is free to pump blood into the area and cause your sleep Attention. In addition to making for wonderful middle school jokes, morning wood is actually important because it pushes extra oxygen into the region, and helps keep your joystick healthy and functional.

It’s also been suggested that NPT is triggered by the release of nitric oxide (NO). NO is released by cells that line the inside of blood vessels which then diffuses into smooth muscle, causing it to relax. This also causes blood vessels to dilate, hence increasing blood flow to the joystick and voila, an Attention. It’s thought that increased activity of part of the pons during REM sleep triggers a cascade of events that ultimately lead to NO release by nerve fibers. This is also regulated by androgens such as testosterone.

So we have discussed how, but what about why? One idea is that these sleep exercises actually contribute to the health of your junk. Erections cause the erectile tissue to swell, which in turn oxygenates the tissue. This oxygenation maintains its viability and helps to prevent cavernous fibrosis, a condition that can ultimately lead to erectile dysfunction.

Another interesting theory is that pitching a tent prevents men from wetting the bed. There are two main types of erections: psychogenic and reflex. The former starts with stimulating thoughts or images which trigger an Attention via nerve signals. The latter is an involuntary process that occurs without sexy thoughts and it’s believed that a full bladder can trigger them. The nerves controlling these reflex erections are located in the sacral nerves of the spinal cord which are also stimulated by a full bladder. Since it’s difficult to pee with a stiffy, it’s thought that NPT may prevent accidental nocturnal enuresis (bed wetting). While this may sound plausible, it seems unlikely because the body has lots of other methods to prevent you from wetting the bed. Furthermore, it doesn’t really make sense given that nocturnal enuresis also affects women.

It seems the most likely explanation is that all of that nighttime mischief is really helping to keep your little man healthy. Be pleased he’s looking out for you.