Munchausen syndrome by proxy (MSBP) is diagnosed if the following criteria are met:²

• Evidence proves that the caregiver is intentionally causing or reporting symptoms in another person under his or her care (a proxy).
• The caregiver seems to be motivated by involvement with the illness of the person under his or her care.
• No outside incentives or motivations (such as payment for false medical claims) account for the caregiver causing or reporting illness in the other person.
• The caregiver is not suffering from any other mental illness.

Doctors who suspect MSBP in a caregiver usually avoid putting the child through unnecessary tests. The child may be admitted to a hospital where he or she is carefully examined and observed. Health professionals also observe first-hand or video-record the caregiver's behavior as they try to discover whether she is producing the symptoms in her child.

A review of past medical records may provide useful information or show inconsistencies about past examinations, tests, treatments, and even hospital stays that can help determine whether a child's illness is real. But if the offending caregiver has provided false information, medical records can be misleading. Medical records may show that the caregiver has frequently consulted new doctors-the caregiver may change doctors to avoid confrontation with evidence of induced or fabricated illness in the child. In rare cases, a doctor gives in to the parent's demands for a diagnosis and treatment to calm a demanding or threatening parent.

If MSBP is confirmed or highly suspected, health professionals are required by law to file a report with the local health department or child welfare agency.