Factitious disorder is a mental illness in which someone tries to convince other people that they’re physically ill. They might pretend to be sick or injured, or try to sicken or injure themselves on purpose.

A person with this disorder might tell doctors they have symptoms that don’t really exist. Or they might alter medical tests to convince their doctor that they need medical treatment, such as surgery.

Individuals with this disorder don’t pretend illness for typical reasons like to get out of work or school or to win a lawsuit.

Experts are unsure why people develop this disorder, but several factors such as childhood trauma, abuse, or neglect, a history of serious disease, or having a family member who was ill seem to play a role.

It’s not clear what motivates individuals with this disorder. While they may receive special attention and sympathy from others, they often experience emotional or physical pain at the same time.

People with factitious disorder may be aware that they’re creating their illness or injury. However, they may not understand why they’re doing it. They also may not see the behavior as a problem.

Some people with factitious disorder may also cause a loved one or family member to become ill. They may lie, telling others that this person is sick or injured.

A parent with factitious disorder may intentionally harm a younger child to make them appear sick or injured. A person may harm adults with disabilities or older adults under their care.

People who do this are generally diagnosed with factitious disorder imposed on another, previously known as “factitious disorder by proxy.” Before that, it was called Munchausen syndrome by proxy.

Factitious disorder by proxy is a form of child abuse.

Risk factors for developing factitious disorder include:

  • abuse as a child (sexual, physical, or emotional abuse)
  • severe illness during childhood
  • having been hospitalized for a medical condition or psychiatric disorder
  • low self-esteem
  • losing a loved one, through death, sickness, or neglect
  • depression
  • a personality disorder
  • desire to spend time with doctors or at medical centers
  • working in the healthcare field or having some medical knowledge

Experts don’t know how many people have factitious disorder, but it’s rare.

It’s hard to get a true estimate since people with this disorder may use false names or visit many different hospitals.

The symptoms of factitious disorder include pretending to have an illness or injury, or exaggerating actual symptoms so that others believe you’re very sick when you aren’t.

Individuals with factitious disorder try very hard to avoid getting caught lying about being sick or injured. For that reason, it can be difficult to realize they have a serious mental health issue.

Symptoms of factitious disorder include:

  • making up symptoms or causing real injuries, for example:
    • exaggerating health problems to appear sicker
    • having symptoms that are easy to fake, such as stomach pain or fainting
    • self-harming to cause illness or injury. For example, a person might expose themselves to bacteria, gasoline, medications, or toxins to get sick. Or they might burn or cut themselves, or interfere with their own healing such as reopening or infecting existing wounds.
    • tampering with medical instruments or tests to alter results. For example, they may heat up a thermometer to make it seem like they have a fever or infection. Or they might taint lab samples, such as urine or blood, with foreign substances.
  • symptoms that are very general or inconsistent
  • health issues that worsen for no clear reasons
  • health problems that don’t respond to treatment
  • receiving treatment from several doctors or hospitals
  • using fake names for healthcare
  • not allowing doctors to talk to friends, family, or other healthcare professionals
  • frequent hospital stays
  • seeking frequent medical tests or serious surgeries
  • having very few or no visitors while in the hospital
  • arguing with doctors, nurses, or medical staff

In factious disorder imposed on another, the main symptom is creating medical problems or symptoms in another person.

People who have factitious disorder often realize that they risk real injury or death, but they cannot control the behavior.

They rarely seek help for the disorder, and may refuse mental health treatment even after others present proof of their deceit — for example, a recording of them walking “normally” when no one’s around, but demonstrating a limp when in the presence of others.

It can be challenging to help a friend or family member with this disorder. If someone you care about has factitious disorder, try to gently express your concerns.

Avoid appearing angry, judgmental, or confrontational.

It may be helpful to encourage this person to focus on healthy, productive behaviors and activities, rather than those that are harmful.

Offer your support and caring, and if possible, help them find mental health counseling and treatment.

Call 911 or your local emergency number immediately if your friend or family member injures themselves or attempts suicide. Or, if possible, safely take them to an emergency room as soon as possible.

It can be very challenging to diagnose factitious disorder.

Those who have the disorder are good at imitating illnesses or causing injuries. Sometimes they may have life-threatening medical conditions that they’ve caused.

Doctors may base a diagnosis on the discovery of false symptoms. They may conduct interviews, ask for all past medical records, speak to close friends or family members, or run additional tests to assess any health problems.

Factitious disorder may be suspected when a person:

  • has a confusing medical history
  • doesn’t have believable reasons for an existing illness or injury
  • has an illness that doesn’t follow a standard course
  • doesn’t heal as expected after treatment
  • shows odd symptoms or test results
  • resists sharing past medical records with other healthcare professionals, friends, or family members
  • gets caught lying about their health or causing self-harm

The treatment of factitious disorder can be very challenging, and there are no standard therapies for the condition. People with factitious disorder may not accept treatment.

The goal of treatment is managing the condition to avoid further mental and physical harm.

Treatment options include:

  • having one primary care doctor oversee all medical care
  • psychotherapy sessions with a mental health professional
  • medication to treat coexisting mental health conditions such as depression or anxiety
  • hospitalization for mental health treatment

With treatment, many people with factitious disorder can remain healthy. It’s important to follow a treatment plan. Regular visits to a mental health professional are very important.