Is there a mental problem that makes people lie?

Pathological lying or mythomania, is the chronic behavior of habitual or compulsive lying, especially about oneself. It is not classified as a mental disorder by the Diagnostic and Statistical Manual of Mental Disorders (DSM). However, it can be a symptom of other mental disorders such as antisocial personality disorder, borderline personality disorder, or narcissistic personality disorder. In many cases compulsive lying becomes a habit without the person realizing they are doing it, making it hard to break.