Trauma Series: Nervous System Dysregulation
One of the most important truths about trauma is this: it doesn’t just live in the mind, it lives in the body. Survivors often describe feeling “on edge,” “numb,” or like their bodies are betraying them. These experiences are not random—they reflect how trauma reorganizes the nervous system.
When the nervous system becomes dysregulated, survivors can swing between states of hyperarousal (anxiety, panic, restlessness) and hypoarousal (numbness, exhaustion, disconnection). Understanding these shifts not only helps explain PTSD symptoms, but also opens the door to healing strategies that target the body as well as the mind.
Trauma and the Autonomic Nervous System
The Autonomic Nervous System (ANS) is responsible for regulating essential bodily functions that we don’t consciously control—breathing, heart rate, digestion, and more. It has two main branches:
The Sympathetic Nervous System (SNS): Activates “fight-or-flight” responses when danger is perceived. Heart rate increases, breathing quickens, and blood flows to the muscles to prepare for action.
The Parasympathetic Nervous System (PNS): Promotes “rest-and-digest” functions, slowing the heart rate and restoring calm once the threat has passed.
In a healthy system, the SNS and PNS work in balance, rising and falling depending on the situation. Trauma, however, disrupts this rhythm.
When Survival Becomes the Default
For trauma survivors, the SNS often becomes overactive. The nervous system learns to expect danger and stays on high alert, even in safe environments. This results in chronic hyperarousal—a state marked by irritability, racing thoughts, insomnia, and a constant feeling of unease.
But trauma can also trigger the opposite: a freeze response. When the body perceives a threat as overwhelming or inescapable, it may shut down into hypoarousal. Survivors in this state may feel numb, disconnected, fatigued, or “spaced out.” This is the body’s way of conserving energy and protecting against overload.
The nervous system can become stuck oscillating between these two extremes, leaving survivors feeling like they are riding an emotional rollercoaster they cannot control.
Polyvagal Theory and Trauma
Neuroscientist Stephen Porges, Ph.D., introduced Polyvagal Theory to explain the complexity of how the vagus nerve regulates our responses to safety and danger. According to this model, the nervous system has three states:
Ventral Vagal (Social Engagement): A state of safety, connection, and calm. This is where healing and growth occur.
Sympathetic (Fight-or-Flight): Mobilized for action when danger is sensed.
Dorsal Vagal (Shutdown/Freeze): A collapse response when the threat feels overwhelming.
Trauma survivors often find themselves stuck in sympathetic overdrive or dorsal shutdown, unable to easily return to ventral vagal safety. Recognizing these states can help survivors understand their triggers and responses with greater compassion.
Symptoms of Nervous System Dysregulation
When the nervous system is dysregulated due to trauma, common symptoms include:
Hyperarousal: racing heart, sweating, rapid breathing, restlessness, anxiety, irritability.
Hypoarousal: fatigue, numbness, dissociation, lack of motivation, difficulty engaging in daily life.
Difficulty shifting between states: feeling “stuck” in high alert or collapse.
Somatic symptoms: chronic pain, digestive issues, headaches, or tension that doesn’t have a clear medical cause.
These symptoms remind us that trauma isn’t “all in your head.” It’s written into the body’s stress-response systems.
Why the Body Remembers
Trauma imprints itself in the nervous system because survival is the body’s highest priority. Even after the threat is gone, the body continues to prepare for danger. This is why triggers—sounds, smells, places, or even internal sensations—can cause survivors to react as though the trauma is happening again.
The body doesn’t distinguish between past and present in these moments. It responds as if survival is at stake.
Healing Through Regulation
The hopeful reality is that the nervous system can relearn balance. Just as trauma dysregulates the body, healing practices can restore regulation.
Effective strategies include:
Somatic therapies (e.g., Somatic Experiencing, Sensorimotor Psychotherapy): These focus on releasing trauma stored in the body.
Breathwork and grounding techniques: Help signal safety to the nervous system in moments of distress.
Yoga and mindful movement: Reconnect the survivor with the body in a safe and empowering way.
Polyvagal-informed therapy: Helps clients recognize their nervous system states and build capacity to shift toward safety.
In therapy, survivors learn not just to cope with trauma, but to rewire the nervous system for safety, connection, and resilience.
Moving Toward Healing
At Dynamic Minds Counseling, we recognize that trauma recovery requires more than talk therapy. Because trauma is stored in both the brain and body, healing must address both. Our trauma-informed approach integrates neurobiology, evidence-based therapies, and body-focused techniques to help clients find relief and reclaim their lives.
Book an intake session today to begin the journey toward nervous system regulation and lasting recovery.
Recommended Reading
The Polyvagal Theory in Therapy by Deb Dana, LCSW – A practical guide to understanding and applying Polyvagal Theory in healing trauma.
Waking the Tiger: Healing Trauma by Peter A. Levine, Ph.D. – Explains how trauma gets stuck in the body and how it can be released.
The Pocket Guide to Polyvagal Theory by Stephen Porges, Ph.D. – An accessible introduction to understanding the nervous system and trauma.
Recommended Podcasts
🎙 The Polyvagal Podcast (Justin Sunseri, LMFT) – Dedicated to understanding Polyvagal Theory and nervous system regulation.
🎙 Transforming Trauma (NARM Training Institute) – Focuses on nervous system healing and trauma recovery.
🎙 Being Well (Dr. Rick Hanson & Forrest Hanson) – Explores neuroscience, resilience, and healing with frequent trauma-focused episodes.
What’s Coming Next on the Blog
This post is the third in a series about trauma. In the coming weeks, we will explore:
Why the Past Feels Like the Present – memory systems, flashbacks, dissociation, and memory fragmentation
Neuroplasticity and Recovery - All about your brain’s ability to heal and rewire itself