Pathological narcissism is a type of narcissism so severe that it causes impairment to the sufferer's life. A certain amount of self-love is considered normal, healthy, and even desirable. A truly pathological narcissist, however, typically has an over-inflated sense of self-worth, and generally believes that he is better than almost anyone. This usually leads the narcissist to treat others terribly, and he is often rude, incredibly demanding, self-centered, and lacking the ability to empathize with other people. Severe narcissism generally stands in the way of interpersonal relationships, so that people suffering from this personality disorder often have few, if any, relationships, and those relationships they do have are often entered into and conducted for the sole benefit of the narcissist, even if the other parties involved wind up grievously hurt.
Psychiatrists have identified a number of personality traits that can indicate pathological narcissism, including excessive self-importance and total disregard for the needs and feelings of others. Many people may have some of the traits of narcissism, but that doesn't necessarily mean they suffer from pathological narcissism. This personality disorder is typically diagnosed when the narcissistic traits are making a normal lifestyle impossible.
True narcissists often find it nearly impossible to carry on a healthy romantic relationship, they typically have few if any friends, and they usually aren't close with their families. They may also suffer from poor performance at work or school, although many people with narcissism are very successful, since their exaggerated sense of pride in themselves can drive them to strive harder professionally and academically. In the worst cases, people with narcissism can find themselves entirely without friends, lovers, or close relations. They may frequently struggle with depression, anxiety, and substance abuse problems.
Psychologists aren't entirely sure what causes pathological narcissism. They believe the personality disorder forms when infants and young children fail to enjoy normal bonding with caregivers. It is, however, rather difficult to study this personality disorder, because people who have it often aren't aware of their condition.
The nature of pathological narcissism is such that the sufferer can never bring himself to recognize his own dysfunctional behavior or to admit that he might have a problem. Narcissists are generally very abusive to others, so that they fail to develop relationships with people who might point out their disordered behaviors. Most psychologists admit that even when narcissists do form relationships, the other parties are typically too frightened of a backlash to point out the narcissist's flaws.