General criteria for such is meeting 5 of the following traits. Note, while this is not meant as a conclusive diagnostic function in any form, perhaps we know some people like this:

A pervasive pattern of grandiosity (in fantasy or behavior), need for admiration, and lack of empathy, beginning by early adulthood and present in a variety of contexts, as indicated by five (or more) of the following:

(1) has a grandiose sense of self-importance (e.g., exaggerates achievements and talents, expects to be recognized as superior without commensurate achievements)

(2) is preoccupied with fantasies of unlimited success, power, brilliance, beauty, or ideal love

(3) believes that he or she is "special" and unique and can only be understood by, or should associate with, other special or high-status people (or institutions)

(4) requires excessive admiration

(5) has a sense of entitlement, i.e., unreasonable expectations of especially favorable treatment or automatic compliance with his or her expectations

(6) is interpersonally exploitative, i.e., takes advantage of others to achieve his or her own ends

(7) lacks empathy: is unwilling to recognize or identify with the feelings and needs of others

(8) is often envious of others or believes that others are envious of him or her

(9) shows arrogant, haughty behaviors or attitudes

Full credit to Dr. Sam Vaknin, who's website, book, and the above excerpt can be found at: http://samvak.tripod.com/npdglance.html

This fulfills the copyright mandate that any reproduction must include the Author's name, and a link to the site.

When you have narcissistic personality disorder, you may come across as conceited, boastful or pretentious. You often monopolize conversations. You may belittle or look down on people you perceive as inferior. You may have a sense of entitlement. And when you don't receive the special treatment to which you feel entitled, you may become very impatient or angry. You may also seek out others you think have the same special talents, power and qualities people you see as equals. You may insist on having "the best" of everything the best car, athletic club, medical care or social circles, for instance.

But underneath all this grandiosity often lies a very fragile self-esteem. You have trouble handling anything that may be perceived as criticism. You may have a sense of secret shame and humiliation. And in order to make yourself feel better, you may react with rage or contempt and efforts to belittle the other person to make yourself appear better.

http://www.mayoclinic.com/health/narcissistic-personality-disorder/DS00652/DSECTION=2