Factitious disorder and malingering !
Factitious disorder means faking or causing illness to be seen as a patient; malingering means faking illness for an external gain such as money or time off.
Updated 2026-11-01
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What it is
Factitious disorder is a mental disorder in which a person deliberately falsifies, exaggerates or induces physical or psychological signs of illness in themselves (factitious disorder imposed on self, formerly Munchausen syndrome) or in another person, usually a child under their care (factitious disorder imposed on another, formerly Munchausen by proxy). The deception happens even without obvious external rewards. Malingering is not a mental disorder: symptoms are faked or exaggerated for a clear external incentive.
Who gets it
Rare but probably under-recognised; found in a small percentage of hospital referrals. Factitious disorder imposed on self is more frequent in women, often with healthcare training. In the imposed-on-another form the perpetrator is most often the mother and the victim a young child. Malingering is more common in legal, insurance, prison, military and disability-benefit settings. Few data exist for Colombia.
Causes
- Factitious disorder: an inner need to take the sick role and receive care and attention
- History of childhood abuse, neglect or serious illness with prolonged hospital care
- Coexisting personality disorders, especially borderline traits
- Malingering: a conscious external goal (money, avoiding work, military service or legal responsibility, obtaining drugs)
Risk factors
- Work or training in healthcare
- Personal history of abuse or early loss
- Borderline or other personality disorder
- Previous unexplained illnesses with many hospital admissions
- For malingering: pending litigation, compensation claims or criminal charges
Pathophysiology
The disorder is psychological, not structural. The person consciously produces the signs (for example injecting insulin, contaminating urine or wounds, taking anticoagulants) but the motivation is largely unconscious: to be cared for as a patient. In malingering both the behaviour and the motive are conscious. This distinction (conscious motive or not) is the core exam point that separates these conditions from conversion and somatic symptom disorders, where the symptoms are not intentionally produced.
Classification
- Factitious disorder imposed on self
- Factitious disorder imposed on another (the perpetrator receives the diagnosis; the victim is a case of abuse)
- Malingering (a V-code, not a mental disorder: intentional symptoms for external gain)
Symptoms and signs
- Dramatic, inconsistent or unusual history that does not match test results
- Many hospitals, doctors and procedures, often with surgical scars
- Eagerness for tests and invasive procedures; new symptoms appear when results are negative
- Signs of self-induction: hypoglycaemia with low C-peptide, infected wounds with unusual organisms, unexplained bleeding
- In the imposed-on-another form: the child's symptoms occur only in the caregiver's presence and stop when separated
- In malingering: vague symptoms, poor cooperation with evaluation and improvement once the external goal is reached
Diagnosis
- Clinical
- Based on evidence of deliberate falsification, gathered from records of other institutions, observation and inconsistencies. Keep an organic differential open. For factitious disorder there is no clear external reward; for malingering there is. The team should document objectively and involve psychiatry early.
- Tests
- Targeted tests that reveal induction: insulin with low C-peptide (exogenous insulin), sulfonylurea screen, urine and blood toxicology, coagulation studies and drug levels (for example anticoagulants), culture of unusual organisms. In suspected imposed-on-another cases, careful supervised observation and, when allowed by law, covert video surveillance.
- Imaging
- Only as needed to rule out genuine disease; avoid repeating invasive studies.
Differential diagnosis
- Genuine medical or neurological disease
- Conversion disorder (functional neurological symptoms, not intentional)
- Somatic symptom disorder and illness anxiety disorder (not intentional)
- Malingering versus factitious disorder (presence or absence of external incentive)
- Borderline personality disorder with self-harm
Goal of treatment
Protect the patient or the victim from harm, stop unnecessary procedures, and engage the person in psychiatric care without humiliating confrontation.
Treatment
- Conservative
- Non-punitive, supportive discussion of findings by the team, with a single coordinating physician and no unnecessary tests or procedures
- Conservative
- Psychotherapy aimed at underlying stress, personality and coping problems
- Acute
- Imposed on another: immediate protection of the child or dependent adult, mandatory report to child protection authorities (in Colombia, ICBF) and separation from the perpetrator as needed
- Conservative
- Malingering: objective documentation, avoid accusation, address the real need and do not prescribe unnecessary drugs
- Medical
- Treatment of coexisting depression or anxiety with appropriate medication classes when indicated
Complications
- Serious harm or death from self-induced illness or from invasive procedures
- Death or severe disability of a child victim; long-term psychological harm
- Drug dependence from repeated prescription of opioids or sedatives
- High healthcare costs and fragmented care across many hospitals
Prognosis
Poor in chronic factitious disorder imposed on self because many patients deny the behaviour and leave care; better when it is linked to a treatable depression or crisis. In the imposed-on-another form, the child's outcome depends on early recognition and protection. Malingering stops when the external incentive disappears.
Test yourself
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What separates factitious disorder from malingering?
Both are intentional; in factitious disorder there is no obvious external reward (the goal is the sick role), while malingering seeks external gain.
A nurse has hypoglycaemia with high insulin and low C-peptide. What does this suggest?
Exogenous insulin injection, a typical sign of factitious disorder.
In factitious disorder imposed on another, what is the first priority?
Protecting the child or victim and reporting to child protection authorities.
Is malingering a mental disorder?
No; it is a behaviour coded as a condition that may be a focus of clinical attention.
Related conditions
- Somatic symptom and illness anxiety disorders
- Functional neurological symptom disorder (conversion disorder)
- Personality disorders (clusters A, B and C)
- Child maltreatment (physical abuse, abusive head trauma, neglect)
- Elder abuse and neglect
- Hypoglycaemia (including insulin-induced)
- Major depressive disorder
- Sepsis and septic shock
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Munchausen syndrome by proxy (MedlinePlus (U.S. National Library of Medicine), 2025).
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