A Hard Topic: The Ins and Outs of Getting (and Keeping) An Erection

This article was scientifically fact-checked by Social Psychologist Dr. Justin Lehmiller.

OK, surely your immediate thoughts are, “Who doesn’t know what an erection is?” And that’s a fair assessment. But do you, really? In actuality, there’s a whole lot more than what meets the eye when it comes to getting hard.

So, sit back and relax, because you’re in for quite the anatomy lesson. Find out some things that may just make you say, “ooh!” and “aah!” when it comes to a man’s pocket rocket.

Here, you’ll find the answers to the intriguing questions:

  • What is an erection?
  • How does a man get an erection?
  • How big is the average erection?
  • How long does the average erection last (and how long is too long)?
  • How often does the average man get an erection?
  • What’s the deal with erectile dysfunction?

You’re also in store for quite a few interesting, and rather surprising, facts about erections! What an adventure!


What is an Erection?

In a technical sense, an erection is when chemical messages are sent to the blood vessels in the penis. The arteries then relax, while the veins constrict. This allows a rush of blood to flow to, and stay inside, the penis – making it hard.

How Does a Man Get an Erection?

When a man is sexually excited! And because every single person is different, sexual arousal can occur for many different reasons… a smell, a taste, an image or video, a touch, and or a thought.

So, when the arousal kicks in, the brain gets all fired up, ready to do the groundwork involved with getting an erection. A true whole-body experience, indeed!

How Big is the Average Erection?

Penis and erection size has already been discussed, at length, in a previous article (you can find it here). But if it’s a TLDR situation, the average size of an erection is 12.9 cm (5.1 inches).

Interestingly, you’ll be glad to know that most women prefer an average-sized penis as opposed to a massive one. So, if you’re average, or even smaller than average, you don’t need to curse the Gods of puberty. In fact, you can count your lucky stars.

Fun fact: did you know that it takes approximately four shot glass-sizes of blood (around 130 ml) to stay hard? Also, blood flows into the penis at a speed of 30 cm per second!

Check this out: Can You Make Your Penis Bigger?

How Long can the Average Man Stay Erect? And How Long is Too Long?

From the point when the penis is at its most erect, the average duration is around 30 to 45 minutes. And while many men wish they could surpass this amount of time after orgasm, it’s physically almost always impossible.

Fun fact: Did you know that the wait time ‘between rounds’ changes depending on a man’s age? For young lads, a cool down period of even five minutes could suffice. But as forty rolls around, you may need a couple of hours.

Then, how long is too long when it comes to maintaining an erection? Four hours.

There’s even a name for those who experience prolonged erections, that is priapism. This condition is not very common, but can be an issue for men who have a blood disorder such as sickle cell anemia.

During priapism, the tissue inside the penis starts to lack oxygen, which then causes some tissue to die. This is not an ideal situation, so anything longer than four hours should definitely be treated by a professional.

Fun fact: this condition is most common in men in their 30’s.

How Often Does the Average Man Get an Erection?

During the span of one day (24 hours), the average man will find themselves with around 10 to 20 erections.

The average amount during the day is 11, while several more (around 3-5) are experienced at night, aka morning wood. But not all of these erections are sexually-induced. Sometimes, a man can gain an erection out of nervousness, anger, or stress.

In conjunction with feeling anxious, angry or stressed, men who have an enlarged prostate, do drugs recreationally, or feel an urgent need to urinate, may also experience non-sexual erections. These are known as “reflex erections”.

What’s the Deal with Erectile Dysfunction?

Erectile Dysfunction (ED) is the most common sexual problem discussed with doctors, and is the inability to achieve or maintain an erection. Physically, there is difficulty when it comes to blood reaching the penis and or staying inside the penis.

ED is most commonly found in older men who have certain medical conditions such as diabetes and heart problems. But it’s equally possible for younger men to experience ED, especially if they are living with psychological issues such as anxiety, depression, fatigue, and or sexual fear.

So while ED is a thing, it’s comforting to know that, with certain treatment and or lifestyle changes, the condition can change for the better or be cured.

Bet You Didn’t Know These Surprising Erection Facts!

An erect penis can break: This happens when the blood vessels inside the penis burst.

This is followed by a cracking sound, swelling and intense pain. Interestingly, it was found that this condition mostly happens when a man’s partner is on top.

A male fetus can experience an erection: While in the womb, a male fetus at around 16 weeks, can begin getting erections.

This is actually normal, and simply proves that the fetus’s nervous system is in great working order.

Shorter penises could equal bigger erections: There’s an expression about being a “grower or a show-er,” and it’s actually entirely accurate. In a study, it was found that men with small flaccid penises could grow in size up to 86 percent when erect.

So, a man could have a seemingly small penis when not erect but could surprise the heck out of his partner once sexually aroused.

An erection isn’t necessary for a male to orgasm: In an erotic situation such as massaging, kissing, fondling, and or oral sex, an orgasm is possible sans an erection. In fact, they can be experienced as normal, if not even more intense, than if an erection was present.

Men experience erections during their sleep: There’s no rest for the wicked. So when a man is peacefully asleep, three to five erections are of normal practice, with each lasting up to 30 minutes.

The most common sleep-time erection is the one when he wakes up (morning wood, morning glory, so on and so forth).

Experiencing an erection during the night isn’t necessarily a sign of sexual arousal though, and is actually an indication of good health.

Ejaculation is spine-chilling: While the brain plays a big role in being sexually aroused, it’s actually the spine that’s responsible for ejaculation. More specifically, a region called the “spinal ejaculation generator”.

It is this part of the body that sends signals to the brain, causing emission and expulsion (ie ejaculation).

Oral sex equals bigger erections: A 2013 study conducted at Indiana University revealed that men actually achieved larger erections from oral sex as opposed to getting the job done themselves by hand.

Less masturbation equals bigger erections: Sex therapist, Ian Kerner, says that when masturbation is done less frequently, the amount of blood that flows into the penis during an erection is higher, causing them to appear fuller and bigger.  

And there you have it! The ins and outs of getting, and keeping, an erection. Did you learn anything new today? You’re welcome!

Facts checked by:

Dr. Justin Lehmiller

Dr. Justin Lehmiller is a social psychologist and Research Fellow at The Kinsey Institute. He is an award-winning educator, having been honored three times with the Certificate of Teaching Excellence from Harvard University, where he taught for several years. Dr. Lehmiller has published more than 50 academic works, including a textbook titled The Psychology of Human Sexuality that is used in college classrooms around the world. He helps people maintain healthy intimate lives through science-based, sex-positive education via his Sex and Psychology blog, workshops, and frequent media appearances.

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