It's called reverse anorexia and it happens to men who believe they are too little and too frail and new research shows its driving men to inject steroids and suffer psychologically.
Muscle dysmorphia affects men whose have normal muscle mass but who believe their muscles are inadequate.
Sydney University research has found men with these body image issues are four times more likely than females with eating disorders to go undiagnosed.
And it says men with these conditions suffer more from depression because of the stigma associated with them seeking help for what is regarded as a female problem.
'The additional stigma towards men is that they are less masculine by virtue of suffering from a stereotypically female problem," the authors say in the study published in the Australian and New Zealand Journal of Public Health.