The sufferer feigns, exaggerates, or creates symptoms of illnesses in themself in order to gain attention, sympathy, and comfort from medical personnel. The role of "patient" is a familiar and comforting one, and it fills a psychological need in the man or woman with Munchausen's.
In the form of the illness known as Munchausen by proxy the "victim" of the illness is usually the patient's child, while their parent gains attention and sympathy as their "worried" mother or father. Munchausen by proxy is a form of child abuse.
The name derives from one Baron Munchhausen (Karl Friedrich Hieronymus Freiherr von Münchhausen, 1720-1797), to whom were ascribed a series of fantastically impossible tales written by Rudolf Raspe.