Penis Dysmorphia is a very real mental disorder. Just as Body Dysmorphia affects the way we see our body, penis dysmorphia changes the reality of how we perceive our penis. Men who have this condition view their penis as abnormally small to the point of shame, humiliation, and isolation. They generally avoid all sexual activity due to these feelings.
While it is perfectly normal for a guy to wonder how he measures up to other guys, this condition goes far beyond that. No amount of proof, evidence, or facts will change their belief that their penis is freakishly small. I had one young man who was convinced he had Micropenis – even though his penis was over 6” long! We talked about penis sizes, looked at charts/graphs, looked at other normal penises – nothing would shake his belief that his penis was too small because he did not look like all the penises he saw in porn. Even when sex partners told him he was bigger than average, he did not believe them. It took several years of therapy and anti-anxiety meds to recover from this belief.
Brian Smith wrote a great article on this for Mel Magazine. He interviews a man who has suffered from penis dysmorphia most of his life. Brian also talks to several specialists, including me, who explore more about this not-so-uncommon condition.