As most people with Munchausen's syndrome refuse to co-operate with any sort of psychiatric treatment or psychological profiling, there is little available evidence on the possible causes of the condition.

There is a consensus of opinion that Munchausen's syndrome is a type of personality disorder. Personality disorders are a class of mental health conditions in which an individual has a distorted pattern of thoughts and beliefs about themselves and others which lead them to behave in ways most people would regard as disturbed and abnormal.

One theory is that people with Munchausen's syndrome have an anti-social personality disorder which causes them to take pleasure in manipulating and deceiving doctors. They may see a doctor as a figure of authority, so tricking these figures of authority, gives them a sense of power and control.

Another theory is that Munchausen's syndrome is an attempt to form relationships and become more socially acceptable. Many people with Munchausen's syndrome are 'loners', have little contact with their family, and have few friends. So they then take comfort in adopting the role of a patient, and find the doctor/patient relationship provides a much needed source of human contact and emotional warmth.

Many people with Munchausen's syndrome have claimed to have experienced physical and sexual abuse during childhood. Though due to their tendency to lie about their past, it is hard to say whether this is actually true in all cases.