COVID-19 Service Update: We are currently dispatching treatments as normal

7 Things You Might Not Know About Penises

Reviewed by
Date published
30/08/2021
Date last updated
22/07/2021
Length of read
5 Minutes

How much do you really know about the male organ? Here are seven facts about penises you may not have known.

1. The Penis Can Break

Although there are no bones in the penis (which is quite rare for mammals), it can actually still break. Vigorous intercourse is the most common cause of a broken penis, but the injury can also be caused by vigorous masturbation or falling on an erection.

The injury can occur when the membrane (named the tunica albuginea) tears and the blood that’s usually confined to this space leaks to the surrounding tissue - resulting in both bruising and swelling.

The tunica albuginea is the membrane that surrounds the corpora cavernosa – the sponge-like tissue inside the penis that engorges with blood during an erection. The moment of fracture not only results in flaccidity but is also generally accompanied by a popping sound, followed by intense pain and swelling. Fortunately, breaking the penis is rare, though recovering from a fracture tends to involve stitches.

2. It’s Twice As Long As It Looks

The penis is actually double the size that is visible to us, with half of it tucked up inside the pelvis, attached to the pubic bone. There’s a mass of erectile tissue which is known as the corpus cavernosum and corpus spongiosum which forms something similar to a boomerang shape, although this is all internal and not visible to the naked eye.

3. Most Men Have 3-5 Erections A Night

Nocturnal penile tumescence, also known as ‘morning wood’, is common among all men and results in them having between 3-5 erections every night. Although it’s not entirely clear why it happens, one of the theories is that it’s to prevent males from wetting the bed, with an erection inhibiting urination – a full bladder can stimulate the nerves in a similar zone to those involved in erections. However, this theory’s validity is doubted due to the fact that women experience a similar function known as nocturnal clitoral tumescence.

Another idea is the link between erections and REM sleep – rapid eye movement sleep. REM sleep has been linked with switching off cells that produce noradrenaline in the locus coeruleus, which is the brainstem. These cells impede on the tone of the penis, and therefore by reducing the obstruction, the penis becomes erect.

Whichever theory is correct, nocturnal erections can be a useful way of diagnosing common issues in the bedroom such as erectile dysfunction. If an erection is achieved when a male is asleep but not when he is awake, the problem is more likely to be psychological, as opposed to physical. For those experiencing such an issue, erectile dysfunction tablets are available to help, as is premature ejaculation treatment.

4. The Penis Can Shrink

It’s not a well-known fact, but the penis can indeed shrink. Smoking is one of the more common reasons for a penis to shrink in size, shortening it by as much as a centimetre due to the calcified blood vessels that reduce erectile circulation. A penis could also potentially shrink by a centimetre or two if not used enough, as the penile tissue becomes less elastic if a man doesn’t experience regular erections. To remain elastic, the penis requires regular bursts of blood flow.

5. An Erection Can Point In Any Direction

Despite what we’re used to seeing in the media, there’s no right or wrong direction for a penis to go. In fact, it’s common for men to have erections that point straight ahead, up or down and left or right. It’s also more common for a man’s penis to curve than be straight (though both are completely normal) with a curve of up to 30 degrees considered normal.

6. First And Last Erection

Not only can ultrasounds sometimes show a foetus with an erection, but it’s also not uncommon for babies to exit the womb with one, either. Studies link this back to REM again, with foetal erections happening most commonly during rapid eye movement, that can occur a number of times an hour.

What’s more, an erection can also occur moments after a man’s death – known as angel lust. It most commonly happens in men who have been hung to death, with researchers believing it’s a result of the pressure of the noose on the cerebellum.

7. The Underside Is the Most Sensitive

The majority of men say the underside of the head (glans) of the penis and the underside of the shaft are the most sensitive areas for sexual pleasure. This sensitivity naturally declines as men age, making it longer for them to become aroused and reach orgasm. Likewise, as you age, your testosterone levels also decrease which makes erectile dysfunction more likely and inhibits rigidity.