Narcissism, or excessive love of oneself, is not just an unattractive trait, it's physically damaging for men too, scientists say.
   

Researchers at the University of Michigan found that men who have this personality trait - characterised by a sense of grandiosity, entitlement and low empathy -- may also have to suffer in terms of their physical health due to more stress encountered in daily activities.
   

However, this does not appear to be the case for women, found the study, LiveScience reported. For their study, published in the journal PLoS ONE, the
researchers recruited over 100 students and gave them a questionnaire that assessed components of narcissism.
   

From these, the researchers got an unhealthy narcissism score by adding up the entitlement and exploitativeness subscales, and they generated a healthy narcissism score by summing up others, including authority, superiority, vanity and self-sufficiency.
   

The researchers also measured levels of a stress-related hormone, cortisol, in the students' saliva at two different times under relatively stress-free conditions.
   

It was found that higher unhealthy narcissism was linked with higher levels of cortisol in men. But, the relationship between the two was much weaker in women.
   

This is problematic for the men as the elevated cortisol levels indicate chronic activation of their body's stress-response system, which can increase their risk of cardiovascular and other problems, the researchers said.
   

Healthy narcissism scores were not related to cortisol levels. It appears narcissism is stressful, study co-author David Reinhard of the University of Virginia said.
   

"Even though narcissists have grandiose self-perceptions, they also have fragile views of themselves, and often resort to defencive strategies like aggression when their sense of superiority is threatened," Reinhard said.