Shan Boodram: Is my penis big enough? 

Personally I don't have one, but this question — and others like it—have put penises in the spotlight since... well, before spotlights were even invented. 

Ancient civilizations idolised them. Early Christians hid them. Calvin Klein ads flaunt them. But when you turn a body part into a symbol, you risk missing out on some pretty crucial information. 

So what's the deal with penises?

Hi! I'm Shan Boodram, and this is Crash Course: Sex Ed.

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Imagine you're at a massive parade. We're talking, marching. And at the end of the procession is the part we've all been waiting for:

The arrival of a giant, golden penis?

This was the vibe of festivals in ancient Greece that honoured the wine god Dionysus. Greeks across the Athens metropolitan area celebrated this symbol of fertility with a one-night-only hookup extravaganza. 

And they weren’t the only ones to celebrate penises. 

The ancient Egyptians carved their gods with larger-than-life elections to represent creation. 

And the ancient Romans believed a phallus could ward off the "evil eye," so they put them on all sorts of things. 

Kinda like me and Frank's RedHot sauce. 

But when Christianity took hold over much of the world, the vibe changed, and it became more common to see the penis as a symbol of evil and sin. 

In the 1560s, the Council of Trent launched a campaign to cover up penises with fig leaves. 

And many women who were accused of witchcraft were actually accused of penis stealing, or having "knowledge of the Devil's penis."

Hate em or love em, the theme was the same: Penises were a big deal. 

And to some degree, I totally get it. I think penises are fascinating! Like, it can just get erect without you telling it to. If you have a penis, you might've had your first erection before you were born, and you could have your last after you die. 

You don’t see that happen in zombie movies. 

But if we just think of penises as a symbol of celebration or sin, we're missing out on learning about actual penises, which are pretty amazing. Just not in the parade float kinda way. 

Unlike the vulva and vagina, we've known how penises work for a long time. At least, once we got past the idea that erect penises were just full of air. 

Early thinkers were pretty fascinated by the D, including Leonardo da Vinci.

Near the end of the 15th century, he dissected human cadavers and drew elaborate sketches of the penis structure, becoming the first to note that erections are not caused by air, but by increased blood flow to the penis. 

And since da Vinci's day, our knowledge of the penis has... kept on growing. 

So let's get on it. 

While the vulva has different holes for peeing and sex, the penis has just one small hole at the end of it. It's called the meatus (nope, I'm not joking), and it's the exit for both urine and semen—the fluid that comes out when a person ejaculates. 

While pee has a relatively straight shot from the bladder out of the body, semen takes... more of a scenic route. After being formed in the testicles, mature sperm travels from a duct call epididymis through a crazy-straw looking tube called vas deferens, and eventually into another tube called the urethra, before its shot out from the meatus during ejaculation. 

And if the penis pulling double-duty makes you think, "Uh, Shan, doesn't that mean I might pee during sex?" Don't worry. 

During arousal, the muscles in the internal urethral sphincter contract, presumably to keep that very thing from happening. 

Now, as for semen — you might assume it's mostly made of sperm, but sperm is only 2-5% of total semen volume. The rest is its entourage of nutrients and carrier liquid that keep the sperm alive and wriggling, and help defend them against the natural acidity of the vagina. 

For a full anatomy lesson, you can check out Crash Course: Anatomy & Physiology. 

But even if you can label a penis diagram with your eyes closed, there's more to it than just the bits and bobs. So, let's grab some questions from the Intimate Inbox. 

Oh here's a good one... "Why do I get an erection while I'm sleeping?"

Right, so, the penis is mostly made of a specialised kind of tissue with tons of tiny blood vessels in it. When blood flow increases, the penis swells, just like how a sponge swells when it's full of water. 

And while this increase in blood flow can happen when you're aroused, it can also happen for seemingly no reason at all, including when you're asleep. 

Overnight, your body regulates itself and its blood flow. Other than that, researchers still don't fully understand why erections happen during sleep — or how often. 

Alright, let's see if I have another one here... "Is it possible to break my penis? I'm SO SCARED of breaking my penis."

Well, I have some great news for you. Even though we use the word "boner" to refer to an erect penis, the human penis doesn't actually have any bones. 

That said, if a penis is forcefully bent while it's erect, the spongy tissue can rupture and tear, which can cause lots of pain and needs immediate medical attention. 

This is called a penis fracture, but I can't stress enough that this is not a common outcome of sex or masturbation, so it's not something to lose sleep, or pleasure, over. 

Okay, here's a question from a non-penis-haver. "When I don’t want to have sex after making out, my boyfriend says he has blue balls. What does that mean?"

I'm so glad you asked this question. The penis isn't the only organ that can swell during arousal. Blood flow to the entire genital area is increased, including to the testicles, to help move semen to the urethra. 

So if someone gets aroused but doesn't ejaculate, it can cause a temporary buildup of blood in the testicles, which can feel uncomfortable. 

Fun fact: the same thing goes for the clitoris! But unless that erection lasts for more than four hours, which actually is a sign of a medical condition, "blue balls" aren't in any way dangerous. 

Ejaculating or just waiting for the arousal to subside will bring relief. And if your partner has blue balls, that isn't something you have to help them with. 

OK. Well, it looks like all the other questions in here are all just the same question: "Is my penis normal?"

And the short answer to that is... probably? I mean, I'm not a doctor. But probably!

If it ever feels like people make a big deal out of penis size, you're right.

In general, Western societies have tended to associate bigger penises with masculinity, fertility, wealth, confidence — all sorts of things that have nothing to do with the actual size of someone's genitals, but can do a great job at making someone feel insecure about themselves. 

Again with the useless symbolism!

So let's cut to the chase. The best estimates we have for average penis size come from a 2023 paper that analysed 75 studies and included over 55,000 measurements from different populations around the world. 

These were the results: an average flaccid length of 3.4 inches and an average erect length of 5.5 inches. 

As for girth, or circumference, another large study found an average flaccid girth of 3.7 inches, and an average erect girth of 4.6 inches. 

Before you whip out the measuring tape, here's the thing: an average is just an average. There's a significant range on either side of that middle number thats considered "normal." 

Plus, research shows that folks with penises are the ones who assign size the most importance. 

One study showed that 85% of women were satisfied with the size of their partner's penis, while only 55% of men were happy with what they had goin' on. 

And in most cases, penis size is pretty unrelated to sexual performance.

Outside of size, there's a lot of variation to penises. Most are darker than the rest of the body and have one tone to the shaft and one tone to the head. Some have visible veins and some penises are straight while others have a slight curve to them—up, down, or to either side. 

And then there's circumcision. You may have heard the words "cut" and "uncut" used to describe circumcised and uncircumcised penises. That's because circumcision, typically performed at birth, is a surgery that removes the layer of skin covering the end of the penis, called the foreskin. 

Folks have been performing circumcisions since ancient times, and it's arguably still the most common surgery performed today. 

Circumcision is chosen for all sorts of reasons, often as part of cultural or religious traditions. And it's become the norm in some places, like the US. While it's definitely not the norm in other places, like the UK. 

It's hard to say exactly why this is, but it could've become cemented in the US healthcare system and culture over time, possibly as a holdover from puritanical attitudes toward sex. 

Puritans used to see circumcision as a cure for masturbation, which they considered unhealthy and sinful. 

And you might be thinking, "But Shan, isn't circumcision more hygienic?"

Well, the jury's out on that one. Most healthcare experts agree that there are some minimal benefits and some minimal risks associated with circumcision — not enough to firmly recommend either way. 

In either case, hygiene is a must. The best way to clean your penis is to pull back the foreskin all the way—if you're uncircumcised—and wash thoroughly but gently using your fingers and warm water. You can also use a gentle, unscented soap. 

So there you have it. Penises might have been the stuff of legend for much of human history, but take away all the symbolism, and it turns out they're just a really cool part of the human body. 

This is just the start of our foray into penises. We'll be talking more about them—and other sex organs—in future episodes. 

Speaking of, next time, we'll talk about what it means to transition. See you then. 

This episode of Crash Course:Sex Ed was produced in partnership with the Kinsey Institute at Indiana University. If you are interested in learning more, visit their website for resources that explore the topics we discussed in the video today. 

Thank you for watching this episode, which was filmed at our studio in Indianapolis and was made with the help of all these nice people. If you want to help keep Crash Course free for everyone forever, you can join our community on Patreon.