A character getting a nosebleed when they see an attractive person is a comedy anime staple that is almost as old as the genre itself. Those who grew up watching anime in the 1990s and early 2000s are likely to have witnessed it at least once, particularly when watching shows with a lot of fan service. But why do the noses of the anime characters start bleeding? And is it possible in real life?
The trope is based on an old wives' tale in which a teenager's blood pressure rises to the point of causing a nosebleed when they see something arousing. The trope is thought to have first appeared in the manga in the 1960s, with mangaka Yasuji Tanioka's humorous comics. Usually, its usage is accompanied by a panty shot or when a character looks more attractive than normal.
The Anime Nosebleed Trope Is Frequently Related to Lewd Old Men
Yuru Yuri's Chitose is notorious for getting them whenever she fantasizes about her friends getting together, mainly Kyouko and Ayano. Master Roshi is also associated with nosebleeds, being the old lecherous man that he is. Ever since Dragon Ball was first released, he has been used as a prime example of the nosebleed trope. His first bloody nose was caused by Bulma flashing him. Since then, he's usually the character that comes to mind when someone thinks about anime and nosebleeds. One Piece's Sanji is another example of a lecherous man getting them frequently.
Karin Maaka from Chibi Vampire is another, albeit extreme, example of the anime nosebleed. While not always due to arousal, she has some of the most intense nosebleeds in anime history. Her waterfalls are caused by the fact that she is a "reverse vampire," or a vampire who produces too much blood rather than craving it. She hunts down unhappy people and bites them, injecting them with her blood, which lifts their spirits.
While they are usually depicted as a normal red color, sometimes instead white steam is shown. Usually, these are shown in shows for smaller kids. It is used to express general excitement rather than arousal. Pokemon's Brock is a good example of this alternate version. Many times, the blood is censored for international audiences, and steam is used instead.
So, how likely is it that sexual arousal will cause a nosebleed? To answer this, consider the two most common causes. The first is nose picking, and the second is prolonged exposure to dry air. The second reason is that they are more common during the winter months. High blood pressure is another cause of nosebleeds. There is also anecdotal evidence of people getting them as a result of overzealous sex.
The Hypothesis That Hormones Cause Anime Nosebleeds Is Not Scientifically Supported
However, there is no scientific proof that sex causes nosebleeds. According to Dr. Kouichirou Kanaya, an ear, nose, and throat specialist, while high blood pressure and an increase in heart rate are unquestionably brought on by sex, nosebleeds are unrelated to it. In other words, having sex does not typically cause nosebleeds in normal people. However, there is evidence showing that the increased blood flow that occurs when men take performance-enhancing drugs like Viagra can cause nosebleeds.
Overall, the nosebleed trope in manga and anime is a perfect way to express the pent-up hormones of teenagers and lecherous men (and sometimes women), even if it has no basis in science. Unless someone is taking specific medication that induces a bloody nose as a side effect, the likelihood of someone getting one from excitement or arousal is slim to none. That doesn't mean we can't laugh when it happens to a character because they got too excited because they saw a pair of panties, though, or when a vampire produces a waterfall of blood instead of consuming it.