Changing narratives, becoming defensive, and adding dramatic details could be signs of a pathological liar. But not always.

Pathological lying — also known as pseudologia fantastica, mythomania, and morbid lying — is a compulsive pattern of telling people things you know aren’t true.

Persistently lying can be an urge so strong that it’s difficult to overcome, similar to how compulsions can become difficult to stop for someone with obsessive-compulsive disorder (OCD).

Pathological lying is an established yet controversial concept in psychology, although it isn’t a mental health diagnosis in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR).

In clinical settings, pathologic lying may be considered a situational occurrence or a symptom of a mental health condition. But with limited research, experts usually explore the behavior in the context of other thinking and behavioral patterns.

Is occasional lying considered pathological?

No, most people lie from time to time and it isn’t an indicator of pathology. Pathological means the behavior may be related to or caused by a health challenge.

If lying and embellishing are a regular occurrence and difficult to control, the behavior may be considered pathological, but context is important.

A 2020 study quantified pathological lying as constantly telling five or more lies in a period of 24 hours, every day, for longer than 6 months.

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If you have a pattern of pathological lying, you may:

  • lie indiscriminately about a wide range of topics
  • tell untruths about minor events
  • feel undeterred by the fear of getting caught
  • experience a rush when you get away with lying
  • continue to lie even when confronted with the truth

“It’s a sign when someone consistently tells stories about extreme, abnormal, or unlikely events that they were involved in,” says Dr. Kyle Zrenchik, a therapist in Minnetonka, Minnesota. “Like befriending celebrities, witnessing a kidnapping, winning a major award, or losing both parents during childhood.”

You may be talking with a pathological liar if you notice:

  • extensive and unrequested details
  • colorful, fantastical, dramatic narratives
  • repeated changes to the story
  • signs of anxiety while talking
  • defensiveness when confronted
  • dodging questions or providing vague answers
  • your recollection of events is different from theirs (feeling gaslit)
  • they “talk the talk” but don’t “walk the walk” (words and actions are incongruent)
  • they retell a story that happened to you and pass it off as their own
  • your gut instinct tells you something is off with their stories

“One study reported that about 13% of people identified themselves as pathological liars,” says Zrenchik.

The cause of pathological lying isn’t established, as the research is limited.

“Researchers are still trying to determine if the brain of a pathological liar forms differently from that of someone who is a ‘normal liar,’” says Zrenchik.

Some mental health conditions may be associated with patterns of pathological lying. These include:

For some, pathological lying may also be linked to childhood trauma. It may have developed as a coping mechanism to help someone get their needs met, says Dr. Nancy Irwin, a licensed clinical psychologist in Los Angeles.

“Typically, they grow up in environments where they learned early on that they are not good enough, that being a flawed human being is unacceptable,” she says. “They more than likely were abused, but surely were emotionally neglected and heavily criticized.”

Do pathological liars believe their lies?

Yes, pathological liars often believe their own lies, according to Zrenchik.

“It can be suggested that the belief does not exist to a delusional level, but potentially due to the repetition and frequency of the lies. It could feel real to the liar because it’s a story they’ve told themselves and others countless times,” he says.

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It can be confusing, frustrating, and traumatic to be constantly lied to, but there are ways to cope.

Try to stay grounded in your sense of reality

When someone lies frequently and believes what they say, it can look sincerely honest, says Zrenchik.

“You may be tempted to question what you believe to be true, giving the other person the benefit of the doubt. Instead, hold firm to what you know to be true and allow the other person to disagree,” he says.

Try to adjust your expectations

If possible, try to give up any expectation that you’ll make them see the truth, or admit you’re right and they’re wrong, says Irwin. You may be sorely disappointed.

“They may not think in the same terms as you do. The ‘truth’ may be a foreign concept to them. The only thing that matters may be ‘winning,’ such as an argument, a lawsuit, or a disagreement,” she says. “They may live in a world of their own reality or truth, which is simply what they need at the moment: a partner, an accomplishment, a deal.”

Try to set healthy boundaries

If you sense you’re being lied to, it’s OK to limit interactions. With composure and calm, try to explain how you feel. “Let them know where you stand and set a boundary for your own self-respect,” says Irwin. “But do so with no expectation of enlightening or changing them and encouraging them to tell the truth.”

Try to be prepared for a confrontation

If things get heated, don’t be afraid to disengage, says Irwin. Even though this doesn’t apply to everyone, “If you try to confront them with evidence and proof of the facts, they may be outraged, insulted, and attack you verbally. They may even badmouth you to others and avoid you.”

Try to encourage them to seek support

Even if they admit to lying, they may not realize how often they lie or see it as indicative of a larger problem, says Zrenchik. It can help to encourage pathological liars to work with a therapist, although you may not want to suggest it as a punishment for lying, he explains. “Instead, suggest it as a means for them to better understand who they are and how they came to perpetuate such behavior.”

Try to learn about body language and ‘tells’

You may find it helpful to watch videos on lie detection from mentalist and hypnotherapist Bedros “Spidey” Akkelian on “The Behavioral Arts” YouTube channel.

Tips from the author

I once dated a person who lied several times a day, from small details to traumatic sagas that never happened. It was devastating. From my experience, you may find it helpful to:

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Anyone can change their behavior, says Zrenchik, if they:

  • are aware of their patterns
  • have sufficient motivation to change
  • practice a new set of behaviors

“The problem with changing someone who is a pathological liar is that, often, they are missing one, two, or three of those necessary components,” he explains. “Often they are not motivated to change, do not acknowledge the existence of the problem, and do not seek nor practice a new behavior.”

Pathological lying is a pattern that becomes evident throughout multiple situations and topics, and persistently over time. It can be a compulsion on its own or a symptom of a mental health condition.

If you are being lied to, try to stay grounded, limit interactions, and set healthy boundaries. You may find it helpful to talk with a therapist if you need support.