Unlocking the Mysteries: Exploring the Profound Link between Trauma and Nightmares

Nightmares can be a distressing experience for anyone. However, for those with Post-Traumatic Stress Disorder (PTSD), they can be particularly debilitating. PTSD nightmares can be vivid and intense, often involving themes, emotions, and experiences related to the traumatic event.

In addition, they can lead to sleep disturbances, which can impact daily functioning and relationships. In this blog, I'll explore the connection between trauma and nightmares through the lens of the neuroscience of the Polyvagal Theory.


Let's first differentiate between the general understanding of PTSD and a more specific Polyvagal understanding of what "trauma" is.

What is PTSD?

"Posttraumatic stress disorder is a psychiatric disorder that may occur in people who have experienced or witnessed a traumatic event, series of events or set of circumstances" (Psychiatry.org). The traumatic event can be a single event, such as a car accident, or a series of events, such as ongoing abuse.

PTSD can lead to various symptoms, including flashbacks, nightmares, and avoidance of situations or places that remind the individual of the traumatic event. It can also lead to various physical symptoms, such as headaches and digestive issues.

Trauma and PTSD are not the same thing. PTSD is a medical diagnosis, a cluster of measurable or observable symptoms stemming from one or more events.

What is trauma?

"Trauma" is typically defined as an experience that overwhelms a person's ability to cope, leaving them feeling helpless, powerless, and vulnerable. It can be a single event or a series of events that cause significant distress.

But we can take our understanding of trauma one step further.

Trauma is not an event that someone went through (like an assault) or events that should have happened that didn't happen (healthy attachment with a caregiver). Instead, it is the impact of those on that person. More specifically, how the event impacts their autonomic nervous system (ANS) state. 

One is "traumatized" when stuck in a biological state of threat. Dr. Stephen Porges teaches us how the autonomic nervous system gets stuck in a defensive state in his Polyvagal Theory.

What is the Polyvagal Theory?

The Polyvagal Theory is basically the neuroscience of how mammals connect in safety and respond to danger. (We wonderful human beings are mammals.) We have three distinct biological pathways that are responsible for the following:

  1. Social engagement - When the ventral vagal parasympathetic pathways are active, we can use social behaviors and connect with ourselves, others, and the present moment.

  2. Flight/Fight Mobility - When the sympathetic pathways are active, we can use mobility to escape or aggress upon a danger.

  3. Shutdown immobility - When the dorsal vagal parasympathetic pathways are active, we can use immobilization to deter a life threat, which immobilizes us to appear dead.

There are many pieces to the Polyvagal Theory. However, I will restrain our discussion to the above and also this - autonomic shifts into and out of danger are not voluntary. One does not choose to leave their social engagement state. When they detect a threat, the biological shift to flight occurs naturally.

The PVT is a biological understanding we apply to trauma and mental health.

Yes, our biology affects every domain of our life, but the PVT is primarily biological. We can then apply that understanding to mental health, relationships, trauma, and even nightmares.

The Polyvagal Theory and Trauma

When it comes to trauma, we get stuck in one of the defensive states. Trauma is the inability to get the body back into its state of safety and social engagement. Or, if a traumatized person can get into their safety state, they will quickly lose access to it when triggered by something familiar to the traumatic incident(s).

For example, a sexual assault victim may be able to access their safety state and have deep friendships. But, when someone unexpectedly gets too close to them with unwelcome touch, it may trigger their body's defensive state. As a result, this individual may go into a complete panic attack. In contrast, an untraumatized person may laugh the situation off when they realize it was someone they knew.

The body is compelled to self-regulate. It must self-regulate into its safe and social state to optimize its resources for "health, growth, and restoration," as the Polyvagal Theory creator often says. In other words, releasing trauma is a biological compulsion, not a conscious choice.

Let's take this understanding to the unconscious world of sleep.

Trauma and Nightmares

What are nightmares?

"Nightmares are vivid dreams that may be threatening, upsetting, bizarre, or otherwise bothersome" (Sleep Foundation). Nightmares can result in the individual waking from sleep and even being fearful of returning to sleep.

These disturbances in sleep typically occur during the rapid eye movement (REM) phase, a stage associated with increased brain activity and vivid dreaming. During this phase, our minds delve into the unconscious, revealing suppressed thoughts, fears, and unresolved conflicts.

Now that we understand the Polyvagal Theory, trauma, and nightmares, let's connect nightmares with the Polyvagal Theory. The first goal is understanding that nightmares are a full-body experience, not just brain images.

Nightmares and Autonomic Activity

Nightmares are not just stories in the brain. Nightmares are something felt and experienced in the body. Numerous physiological state shifts accompany nightmares:

  • increased heart rate

  • increased breathing rate

  • sweating

  • increased blood pressure

  • muscle twitching or REM behavior disorder

  • pupil dilation

  • increased body temperature

These physiological state shifts are all autonomic. In a non-lab sleep study, they "...found an increase in various autonomic measures (e.g., electrodermal measures, heart rate measures, breathing cycle length, REM density) when experiencing nightmares compared to normal dreams (Paul et al.)".

In particular, these state shifts are all indicative of a sympathetic autonomic state. In simple Polyvagal terms - the flight/fight state. These autonomic shifts could also indicate the Polyvagal freeze mixed state, a combination of flight/fight activity and shutdown. One is in shutdown when sleeping, so this makes sense on an obvious level.

However, when one survives an acute traumatic incident, they often enter the freeze mixed state. For example, during a sexual assault, the victim will likely be activated to run or fight but also be immobilized simultaneously. The immobilization could come through force or perception. Either way, there is an involuntary freeze response.

The flight/fight sympathetic activation is frozen into the system through the immobilization of shutdown. But the frozen flight/fight energy naturally needs to release.

Remember - the body is compelled to self-regulate. It must. That is its biological imperative. And self-regulation means releasing stuck trauma, exiting from a defensive state, and back into the ideal state of safety and social engagement where resources are optimized.

During sleep, the body still attempts to self-regulate. But when asleep, nothing gets in the way. The person awake can distract themselves with their phone and numb the pains of trauma. When sleeping, there is no such distraction.

Instead, there is simply the biological imperative of self-regulation. So how do dreams connect to this biological imperative?

Polyvagal Theory "Story Follow State" and Nightmares

"Story follows state" is a concept from Deb Dana. Those three simple words explain a significant idea - the cognitions in our brain come from the state of our autonomic nervous system. Our "stories" sound different based on our state:

  • safety state - "I believe in myself."

  • flight/fight state - "They're going to laugh at me!"

  • Shutdown state - "What's the point of even trying?"

The primary factor is the state of the ANS. So during sleep, when the ANS attempts to self-regulate, the stories in our mind change along with it.

For someone living in a traumatized state, the ANS needs to self-regulate out of that state, which means that state will be experienced during sleep. And then, thoughts follow, resulting in a very realistic re-living of the event or a nightmare reflecting the traumatic events' experience.

"Post-traumatic nightmares often involve elements similar to the trauma itself, according to the National Center for PTSD of the U.S. Department of Veterans Affairs. About half of the people who have nightmares after a traumatic event have nightmares that replay the trauma[tic event]. Those with PTSD are much more likely to have exact replays of their trauma[tic event]" (Harvard).

Umbrella Understanding of Nightmares and PTSD

This was a lot, I know. Here's the overarching umbrella understanding:

  • trauma is being stuck in a defensive state

  • the ANS must self-regulate and attempts to do so all the time, even when asleep

  • the thoughts in our brain come from the state of the ANS

  • nightmare stories happen due to the unfiltered thoughts that come from the ANS' attempts to self-regulate when asleep

How to resolve PTSD nightmares

There are more and more evidence-based methods to help us recover from PTSD and get rid of nightmares. Dr. Yishan offers treatment for insomnia and nightmares, and Mind Body Garden Psychology clinic has many psychotherapists who offer treatment for PTSD and trauma. You can check out this video where Dr. Yishan explains some science behind the nightmare and tips for coping with it.

Self-regulate to recover from trauma

To reduce or eliminate nightmares, you first need to alleviate your trauma. To do so, this requires one thing - self-regulate out of a defensive state and access your state of safety and social engagement.

Is it easy? No.

Is it possible? Yes.

And when you do successfully do so, you should notice a significant reduction in the frequency and intensity of nightmares. My therapy clients improve in nightmares, emotional regulation, and overall life satisfaction as they gain more access to their safety state.

I created a trauma-recovery program called the Polyvagal Trauma Relief System. PTRS is based on my deep knowledge and application of the Polyvagal Theory. PTRS helps you to recover from trauma in three phases:

  1. simply and clearly learn about the Polyvagal Theory.

  2. identify safety, practice being in your safety state, and build the strength of your safety state.

  3. actively and mindfully experience the stuck trauma while being anchored in your safety state, opening the possibility of self-regulation to occur.

You can learn more about PTRS on my website by clicking here.

Learn more about the Polyvagal Theory:

If you want to read more about the Polyvagal Theory and like the highly academic, nerdy stuff, then this is the source for you. On the other hand, if you want something more approachable but helpful, read about the Polyvagal Theory for free in my Polyvagal Intro.

About the Author

Justin Sunseri is a licensed Marriage and Family Therapist and Coach specializing in trauma relief. He hosts the Stuck Not Broken podcast and is the author of the book Trauma & the Polyvagal Paradigm. He specializes in treating trauma and helps individuals get "unstuck" from their defensive states.

Non-linked citation:

*Paul F, Alpers GW, Reinhard I, Schredl M. Nightmares do result in psychophysiological arousal: A multimeasure ambulatory assessment study. Psychophysiology. 2019 Jul;56(7):e13366. doi: 10.1111/psyp.13366. Epub 2019 Mar 30. PMID: 30927477.

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