A personality disorder is a type of mental disorder in which you have a rigid and unhealthy pattern of thinking, functioning and behaving. A person with a personality disorder has trouble perceiving and relating to situations and people. This causes significant problems and limitations in relationships, social activities, work and school. In some cases, the individuals may not realize that they have a personality disorder because their way of thinking and behaving seems natural to them. It is also possible that they may blame others for the challenges they face. There are ten types of personality disorders: paranoid personality disorder, schizoid personality disorder, schizotypical personality disorder, antisocial personality disorder, borderline personality disorder, histrionic personality disorder, narcissistic personality disorder, avoidant personality disorder, dependent personality disorder, obsessive – compulsive personality disorder.