Fight or flight is a common response to a threat or danger. Your brain triggers these actions to protect you.

You might push and shove if a stranger grabs you. Or you might sprint out of the way of an oncoming car.

Sometimes a threat can cause you to freeze instead of fighting or fleeing. If you’ve ever been unable to move to protect yourself or call for help, you may have experienced tonic immobility, aka trauma-induced paralysis.

Tonic immobility is a trauma response. It’s an involuntary inability to move or even speak.

If you encounter a traumatic situation, you might freeze briefly before defending yourself or trying to escape.

But if you stay frozen and can’t react, you may be experiencing what is called tonic immobility or trauma-induced paralysis.

Freezing and tonic immobility are both responses to trauma. Since they have similar characteristics, you might hear the terms used interchangeably. But freezing and tonic immobility are different.

Freezing occurs at the first encounter with the threat, and tonic immobility is the threat-induced paralysis that leaves you unable to take action.

Tonic immobility is a part of the human defense cascade, according to research from 2015. This includes:

  • Arousal: the first awareness of a threat
  • Fight or flight: an active response
  • Freeze: a short delay before fight or flight
  • Tonic immobility (paralysis) and collapsed immobility (fainting): the response when the threat is inescapable
  • Quiescent immobility: rest and recovery

In animals, tonic immobility activates on contact with a predator. The immobility is to calm the predator’s killing reflex. It can also discourage the predator from eating the prey since carnivorous animals usually prefer live food.

In humans, tonic immobility can occur as a defense reaction to extreme fear.

Tonic immobility is a common response during a sexual assault. In a 2017 study, researchers assessed tonic immobility in 298 females — all survivors of sexual assault — using the Tonic Immobility Scale.

They found that 70% of the females reported experiencing significant tonic immobility, and 48% reported tonic immobility that was “extreme.”

The study also found that tonic immobility was associated with post-traumatic stress disorder (PTSD) and depression 6 months after the assault.

Research from 2016 shows that extreme tonic immobility is more common in people who’ve experienced:

If you’ve experienced a similar trauma more than once, it’s possible to skip the flight, fight, and freeze response and go directly from a state of arousal into tonic immobility.

There’s more than one way to manage PTSD from a trauma that’s caused tonic immobility. If you find the approach you’ve tried hasn’t helped, there are other options to consider.

Common trauma treatments include:

  • Cognitive behavioral therapy (CBT): identifying and changing distressing thought patterns
  • Prolonged exposure therapy (PE): confronting triggers in a safe, supportive environment
  • Eye movement desensitization and reprocessing (EMDR): reprocessing stressful memories

Trauma-informed mindfulness may also help. If you’re interested in trying this approach, it’s recommended that you work with a trauma-informed mindfulness teacher who can help you create a safe environment to manage your trigger exposure.

Another option to investigate is tonic immobility psychoeducation (TIP), studied in a 2021 clinical trial.

Psychoeducation is useful for a range of mental and physical health conditions. It teaches you about the issue you’re living with to aid in your understanding and validate your experience.

Self-care between therapy sessions can also help. Restorative sleep, nutrition, exercise, and nurturing social connections are examples of areas you may be able to improve.

If you’ve experienced tonic immobility during or following trauma and live with post-traumatic stress disorder as a result, it’s a good idea to consider seeking some mental health support.

You might feel reluctant to seek help because you’re concerned about how others might perceive your tonic immobility trauma response. You might worry they’ll think you should have done something rather than stayed immobile.

It’s crucial to remember that tonic immobility is an involuntary reaction. You didn’t choose passivity, and it’s not the same thing as consent.

Instead, your nervous system set in motion a series of signals and hormones that left you unable to move or speak, even though you wanted the trauma to stop.

You don’t have to question or blame yourself for your reaction. You can feel empowered to seek help if you think you need it.

If you’re not sure how to find support, browsing through some resource options is one way to start.

Psych Central has some pages you might find helpful:

The U.S. Department of Veterans Affairs has a Get Help page for people living with PTSD.

The National Sexual Violence Resource Center has a comprehensive list of online communities offering support and help.

Healthline also offers a list of online PTSD support groups.

Tonic immobility is a trauma response that occurs when your nervous system decides it’s unsafe to fight or flee. It’s common among survivors of sexual violence.

Tonic immobility isn’t a choice, and it doesn’t imply consent. Trauma-induced paralysis isn’t something you’ve “done wrong.” It’s a natural reflex.

There’s a connection between tonic immobility and PTSD. Treatment can help, so it’s crucial to reach out for support if you think you need it.