30 Interesting Erection Facts

By Karin Lehnardt, Senior Writer

Published July 8, 2018Updated September 9, 2019

Between 20 million and 30 million men in the United States experience some degree of erectile dysfunction._[4]
Erections are necessary for penile health. When the penis is erect, it is filled with fresh, oxygen rich blood._[4]
There are three kinds of erections: 1) reflexogenic erections come from actual physical contact, 2) psychogenic erections come from audiovisual stimulation or fantasy, and 3) nocturnal erections take place at night. The last two types aren't always intentional._[14]
Drinking or smoking can lead to erectile dysfunction._[4]
The average American man's penis size when erect is 5.6 inches long. The average erect penis circumference is 4.8 inches._[5]

Alternative terms for this condition include ithyphallophobia or medorthophobia

"Phallophobia" is the fear of or aversion to an erect penis._[10]
Staying up all night or sleeping with a partner who snores affects a man's sleep cycle, which, in turn, affects the normal cycle of erections that happen during the night._[13]
Some men have a penis that curves upward, downward, or to the side when erect. A bent erect penis is only a problem if erections are painful or if the curvature interferes with sex._[1]
Size, as in body size, matters. Obese men have lower testosterone levels, which means they may have a harder time achieving an erection._[4]
Erections are common in children and infants, even occurring before birth._[12]
Erect penises can break. Since there aren't bones in a penis, a "broken" penis is when the blood vessels burst, which causes painful swelling. One-third of penile fractures occur when a sexual partner is on top._[15]
Erectile dysfunction medications work about 2/3 of the time. Some men need increasingly larger doses, which can increase the side effects of the medication, including headaches, hot flashes, upset stomach, and dizziness._[3]
For every extra 30 pounds a man carries, his penis shaft is buried by about an inch._[2]
Jonah Falcon is believed to have the world's largest penis. Erect, his penis is over 1 foot long. When flaccid, it measures 9.5 inches._[8]
A healthy man, on average, has 3–5 erections during the night. Each erection lasts about 25–35 minutes._[4]

The penis does not obey the order of its master, who tries to erect or shrink it at will, whereas instead the penis erects freely while its master is asleep. The penis must be said to have its own mind.

- Leonardo da Vinci

Men with smaller, shorter penises have erections that can increase penis size by 86%. For longer penises, penis size increases by about 47%._[2]
Men commonly wake up with an erection, informally nicknamed a "morning glory."_[4]
One nickname for a penis is "love muscle"; however, a penis is not a muscle. An erect penis is more like a sponge that has filled with blood._[4]
Priapism is a medical emergency in which a penis remains erect for longer than 4 hours. It is a painful condition that is unrelated to sexual arousal or stimulation._[11]
There is a condition called "koro," in which a man is irrationally afraid that his penis will shrink back into his body. Koro syndrome sufferers believe that they will die when their genitals disappear._[17]
A "death erection" is a post-mortem erection, especially in men who have been executed by hanging. Technically it is a priapism (when blood gets trapped in the penis), the phenomena occurs when the noose puts pressure on the cerebellum._[7]
Oral sex typically leads to a larger erection than other types of arousal methods._[5]

Not all erections are created equal

Every year, Japan holds the Shinto Kanamara Matsuri, which is also known as the "Festival of the Steel Phallus." During the event, people parade giant phallic-shaped shrines, suck on penis lollipops, buy penis-themed memorabilia, and pose with sculptures of erect penises._[6]
A healthy male averages about 11 erections per day; nine of these occur at night._[7]
On average, an erect penis will contain over eight to ten times its normal amount of blood._[16]
Researchers estimate that less than 5,000 men on earth have an erect penis over 11 inches long._[16]
Certain smells can increase penile blood flow during an erection, such as licorice, pumpkin pie, lavender, donuts, and chocolate._[16]

The smell of doughnuts can increase penile blood flow

Scientists speculate that the head of a human penis evolved into its current mushroom shape in order to scoop rival male's sperm out of the vagina._[16]
Nitric oxide triggers blood flow to the penis to create an erection. This chemical is also produced naturally by lightning strikes._[16]
The bite of the Brazilian wandering spider can cause long and painful erections, as well as other symptoms, in human males._[9]