A personality disorder is a type of mental disorder in which a person has 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.

It is not clear exactly what causes personality disorders, but they're thought to result from a combination of the genes a person inherits and early environmental influences – for example, a distressing childhood experience (such as abuse or neglect)

In some cases, people may not realize that they have a personality disorder because their behavior and way of thinking seem natural to them. They may perceive that other people are to blame for the challenges they face.

Having a personality disorder can have a big effect on a person's life, as well as their family and friends. Untreated personality disorders can cause significant problems in life that may get worse without mental health support. This is why it is important to seek professional mental health support if you suspect that you or someone close to you is suffering from such disorders.

Treatment for a personality disorder usually involves psychotherapy. This is where the person talks to a therapist to get a better understanding of his/her own thoughts, feelings, and behaviours.