The average size of an erect penis is *big drumroll* 5.8 inches. Which, as an iconic study from 2013 discovered, is smaller than most men (people who have penises they could measure on their own) think it is.
And in an online survey from 2006 of more than 25,000 men, almost half of the participants said they were unhappy with their dick size—with 45 percent saying they wished it were bigger. Most of those men, the survey reports, have penises that fall within the range of what's considered normal.
It's upsetting, but not necessarily surprising. Wanting to have a larger dick is just one of the many bad side effects of living in a world that places weird, arbitrary expectations on what being a man is supposed to look like.
But sometimes fixation on dick size, and obsession with wanting a larger one, hits an unhealthy point and disrupts a guy's sex and romantic life. It's a relatively recently identified phenomenon called penile dysmorphic disorder, or PDD. You can think of it the same way you do body dysmorphic disorder, just localized to one very specific body part: A guy looks down at his perfectly good penis and sees something else entirely, causing anxiety and depression that interfere with other aspects of his life.
Research on PDD is new—you won't find it in the DSM and it's not something a lot of health-care providers recognize just yet, explains Justin Lehmiller, PhD, research fellow at the Kinsey Institute and author of Tell Me What You Want. A study published in Archives of Sexual Behavior in 2015 was the first to establish screening guidelines that help identify PDD versus passive thoughts about wishing for a bigger dick.
PDD can also keep a guy from seeking out romantic partners in the first place and even cause performance issues at work.
What separates the two is that for dick anxiety to be considered PDD "it has to be causing distress where it might negatively impact sexual function," Lehmiller says, like making it difficult for a guy to get or stay hard. PDD can also keep a guy from seeking out romantic partners in the first place and even cause performance issues at work. "We're talking about people for whom the concern really gets out of hand," Lehmiller says.
The key is that PDD is a perception bias—so a guy with a normal dick looks at it and sees it as insufficient. "The question is, where did that perception bias come from?" Lehmiller says. "A big part of the problem is in pornography, where we constantly get messages that bigger is better, and penis size is the measure of manhood. All of those things create cultural pressure on men."
The sources of perception bias—impossibly dicked men in porn, as Lehmiller mentions—could be one reason why PDD is only just now entering the penile lexicon. Because it's all so recent, there's not reliable data on how common PDD is and who's most likely to struggle with it. "But I would suspect that this could be more prevalent in younger generations who've been exposed to more porn," Lehmiller says.
"A big part of the problem is in pornography, where we constantly get messages that bigger is better, and penis size is the measure of manhood. All of those things create cultural pressure on men."
That's not to say that all porn is evil and bad and making men turn against their own penises. But believing in what porn portrays—the elephant-trunk dicks that stay hard for 45 uninterrupted minutes—is part of the problem. Previous studies, for example, have found an association between overuse of porn and ED, but not necessarily a link between watching porn occasionally and sexual dysfunction.
Left undiagnosed and untreated, PDD causes anxiety, problems with ED, and disrupts an otherwise healthy guy's ability to have sexual relationships. Lehmiller also writes that it may lead some men to seek out highly experimental penile enlargement procedures that often leave guys feeling worse rather than better.
If you think your partner might be struggling with PDD, gently remind him what most women say over and over again: Size doesn't matter. And if he needs reassurance you can't provide, suggest (outside of the bedroom, when you're both clothed) that he might feel better by seeing a sex-friendly therapist.
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This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.