Munchausen syndrome is a poorly understood disorder, and its causes are not known. However, some psychological and biological factors may be involved. Some experts suggest that Munchausen syndrome may be a form of self-punishment. Other theories suggest the syndrome may be a form of self-defense against impulses that are sexual or aggressive.

Other factors that have been linked to Munchausen syndrome include a history of abuse or neglect as a child or a history of hospitalizations. It also appears to be more likely to occur among people who have healthcare professionals in their families. However, it is unclear if the development of the disorder is a result of this or if these people are simply able to provide what appears to be a more valid medical history because they are more knowledgeable about medical conditions.

Research into the disorder has been extremely difficult because patients with Munchausen syndrome usually hide their condition from others and typically seek out other healthcare professionals when they are confronted about their subterfuge.

Men appear to be at greater risk than women for the most chronic and severe forms of Munchausen syndrome.