Munchausen syndrome is a condition in which a patient regularly feigns illness or injury in order to receive medical treatment. Patients with the condition may be hospitalized repeatedly for short stays or travel from place to place searching for care. It is the most severe form of factitious disorder, in which patients intentionally produce or fake physical or psychological symptoms to convince others they are sick.

Patients with Munchausen syndrome tend to report signs or symptoms of physical illness (e.g., stomachache, chest pain, fever). Munchausen syndrome is sometimes used interchangeably with the term "factitious disorder." However, patients with Munchausen syndrome tend to lie about physical, rather than psychological, symptoms. This form of factitious disorder is named after Baron von Munchausen, an 18^th century German nobleman who became a famed teller of tall tales. Although most factitious disorders are more common in females than males, the most chronic and severe cases of Munchausen syndrome generally occur in males.

The causes of Munchausen syndrome are not completely understood. The specific symptoms of Munchausen syndrome depend upon the type of disorder that a patient chooses to fake. In most cases, patients complain of physical symptoms or exhibit signs of physical illness, such as chest pain, stomach problems or fever. Patients often injure themselves to create physical symptoms.

At first, it may not be obvious to a physician that a patient is faking symptoms. This may become clear, though, when test results come back negative or treatments fail to cure the patient’s alleged symptoms. Once a physician suspects a patient of feigning illness, a psychiatrist, psychologist or other mental health professional may be brought in to help diagnose the patient’s true disorder.

Patients with Munchausen syndrome typically lie about their illness and refuse to admit that they are not sick. As a result, the prognosis for treating this condition is very poor. Patients who are willing to seek help may benefit from psychotherapy, which helps them explore the root of their compulsion for lying about illness.

Munchausen syndrome should not be confused with Munchausen syndrome by proxy (MSBP), a condition in which a parent or other caregiver fabricates or exaggerates the symptoms of someone – usually a child – under their care in order to receive attention in a medical setting.