Münchhausen or Munchausen refer to Baron Munchausen (1720–1797), a German nobleman whose adventurous life was later fictionalized in literature and film.
Munchausen Syndrome is a type of factitious disorder, in which a person deliberately produces or fakes symptoms of a physical or mental illness in order to assume the sick role and be seen as a patient. This disorder is named after Baron von Munchausen, an 18th-century German officer who was known for telling exaggerated stories about his experiences.
For example, a person with Munchausen syndrome might repeatedly visit emergency rooms and doctors' offices, claiming to have a variety of serious illnesses, but never staying long enough for a proper diagnosis or treatment. They may also fabricate or induce symptoms, such as injecting themselves with bacteria to produce an infection, or taking drugs that cause side effects to mimic a disease.
Munchausen by proxy is a specific subtype of the disorder in which a caretaker, often a parent, induces illness in another person, such as a child, for attention and sympathy.
It's worth noting that Munchausen Syndrome is a relatively rare disorder and the diagnosis should be made by a qualified mental health professional.