Pathological narcissism is a life-long pattern of traits and behaviours which signify infatuation and obsession with one's self to the exclusion of all others and the egotistic and ruthless pursuit of one's gratification, dominance, and ambition.
As distinct from healthy narcissism, which we all possess, pathological narcissism is maladaptive, rigid, persisting, and causes significant distress and functional impairment.