Egomania is a psychiatric term used to describe excessive preoccupation with one's ego, identity or self and applies the same preoccupation to anyone who follows one’s own ungoverned impulses, is possessed by delusions of personal greatness & grandeur and feels a lack of appreciation. Someone suffering from this extreme egocentric focus is an egomaniac. Egomania as a condition, while not a classified personality disorder, is considered psychologically abnormal.
The term egomania is often used by laypersons in a pejorative fashion to describe an individual who is perceived as intolerably self-centered. The clinical condition that most resembles egomania, and most often associated with is narcissistic personality disorder, though they differ vastly according to the individual's responses to others.