Polyvagal Theory & the Nervous System: How Stress Wires Your Body & How to Rewire It
The nervous system is the body’s master control system, constantly scanning the environment to determine whether we are safe or in danger. Every function in our body—breathing, digestion, movement, immune response—is dictated by its ability to regulate and adapt.
The autonomic nervous system (ANS) governs these processes automatically, ensuring our body responds appropriately to its surroundings. It does this through two main divisions:
1️⃣ The Sympathetic Nervous System (SNS) – Often labeled as the "fight or flight" system, but this is an oversimplification. While it does prepare us to react to danger, it also plays a vital role in engagement, motivation, focus, and physical activity. Proper activation of the sympathetic system helps us exercise, pursue goals, and stay alert. However, chronic stress can wire the nervous system to stay in a heightened state, leading to anxiety, poor digestion, and immune suppression.
2️⃣ The Parasympathetic Nervous System (PNS) – Commonly referred to as the "rest and digest" system, this branch allows the body to heal, regulate emotions, and recover. When active, it supports digestion, heart rate variability, and immune function. However, if overwhelmed, the parasympathetic system can shift into dorsal vagal shutdown, leading to chronic fatigue, depression, or dissociation.
These systems are not meant to work in isolation—they should dynamically shift based on need. However, chronic stress, trauma, and environmental stressors can cause dysregulation, where a person gets stuck in one mode or, over time, becomes wired to default to an imbalanced state.
The 3 T’s: How Stress Wires the Nervous System
The body experiences stress in three primary ways, known in chiropractic as the Three T’s:
✔️ Thoughts (Emotional Stress) – Chronic worry, fear, and overstimulation create ongoing sympathetic activation, making it harder to relax and recover. ✔️ Traumas (Physical Stress) – Birth trauma, falls, poor posture, or injuries affect nervous system regulation, keeping the body in a stress response. ✔️ Toxins (Chemical Stress) – Processed foods, environmental toxins, and medications can overload the system, impairing digestion, energy, and cognitive function.
Each of these stressors can wire the nervous system into an altered state, making it difficult to transition between sympathetic and parasympathetic functions fluidly.
The Vagus Nerve: The Bridge Between Safety and Survival
The vagus nerve is the longest cranial nerve in the body, running from the brainstem through the heart, lungs, and digestive tract. It plays a crucial role in regulating autonomic function and is divided into two branches:
1️⃣ Ventral Vagal Pathway (Safe & Social Mode) – This part of the vagus nerve is responsible for emotional regulation, social engagement, and adaptability to stress. When activated, it allows for rational thinking, connection, and ease in daily life.
2️⃣ Dorsal Vagal Pathway (Shutdown Mode) – This older, more primitive part of the vagus nerve activates when stress becomes too overwhelming. Instead of mobilizing energy to fight or flee, it conserves energy by slowing everything down, leading to feelings of disconnection, fatigue, and even dissociation.
Every single day, our nervous system navigates between these states—sometimes fluidly, sometimes getting stuck. Whether due to early life experiences, chronic stress, or unresolved trauma, our body learns patterns of response that influence our health, behavior, and emotions.
How Early Life Experiences Shape the Nervous System
Our nervous system wiring begins in the womb. Maternal stress, birth trauma, and early childhood experiences all shape how our nervous system responds to the world.
Prenatal Stress – When a mother experiences chronic stress, her baby’s nervous system adapts to that same stress state, wiring the infant for heightened reactivity or withdrawal before they are even born.
Birth Trauma – Difficult deliveries, medical interventions, or lack of skin-to-skin contact after birth can disrupt the development of a baby’s autonomic regulation.
Early Attachment & Regulation – A baby learns to regulate their own nervous system by co-regulating with their caregivers. If a parent is in chronic stress or anxious states, the baby may develop a nervous system that struggles to feel safe.
If a child’s nervous system is not properly balanced in these early years, they may show signs of sensory sensitivities, emotional dysregulation, poor digestion, or developmental delays.
Chronic Dysregulation: When the Nervous System Gets Stuck
Ideally, we should be able to move fluidly between these autonomic states, activating fight-or-flight when needed but returning to a calm, ventral vagal state when the stressor is gone. However, chronic stress, trauma, and lack of regulation can cause the nervous system to become "stuck," leading to:
✔️ Anxiety, panic, and chronic stress ✔️ Poor digestion (IBS, reflux, constipation) ✔️ Emotional dysregulation and sensory sensitivities ✔️ Fatigue, brain fog, and difficulty recovering from stress ✔️ Immune dysfunction and chronic inflammation
This is why addressing nervous system regulation is so crucial to overall health and healing.
The Role of Chiropractic Care in Nervous System Regulation
Now for the good news—the nervous system can be rewired. Chiropractic care plays a direct role in restoring vagus nerve function, balancing the autonomic nervous system, and improving adaptability to stress.
Dr. Heidi Haavik’s research has shown that chiropractic care enhances prefrontal cortex function, which plays a crucial role in nervous system adaptability, cognitive function, and emotional regulation. This means that chiropractic adjustments don’t just influence muscles and joints—they impact brain function and autonomic regulation at a deep level.
✅ Chiropractic Adjustments Stimulate Vagal Tone – Adjustments activate the vagus nerve, enhancing its ability to regulate heart rate, digestion, and immune function. ✅ Reducing Tension in the Brainstem & Spinal Cord – Because the vagus nerve originates in the brainstem, any interference in the nervous system can impact its function. ✅ Improving Prefrontal Cortex Function – By enhancing the nervous system’s ability to shift between states, chiropractic care supports emotional regulation, resilience, and cognitive control. ✅ Enhancing the Nervous System’s Ability to Adapt – Chiropractic care helps the body move between autonomic states more efficiently, reducing the likelihood of getting stuck in fight-or-flight or freeze mode.
Polyvagal Theory & Chiropractic: A Powerful Approach to Healing
By understanding how the nervous system operates through Polyvagal Theory, we can see that health isn’t just about symptoms—it’s about regulation. Chiropractic care is one of the most powerful ways to support nervous system balance, allowing the body to shift out of stress and into healing.
📅 Schedule a consultation today to learn how chiropractic can support your nervous system, activate the vagus nerve, and help your body shift out of stress and into healing.
