Pathological lying (also called pseudologia fantastica and mythomania), is a behavior of habitual or compulsive lying. It was first described in the medical literature in 1891 by Anton Delbrueck. Although it is a controversial topic, pathological lying has been defined as "falsification entirely disproportionate to any discernible end in view, may be extensive and very complicated, and may manifest over a period of years or even a lifetime". The individual may be aware they are lying, or may believe they are telling the truth.
Defining characteristics of pathological lying include: