If you’ve experienced trauma, anxiety, or simply struggle to feel safe in your own body, understanding polyvagal theory may offer valuable insight into why your nervous system responds the way it does—and what might help.
Developed by neuroscientist Dr Stephen Porges in 1994, polyvagal theory provides a framework for understanding how our autonomic nervous system influences our emotions, behaviours, and capacity for connection. For many people navigating trauma recovery, this theory offers something profound: a way to make sense of responses that may have previously felt confusing, shameful, or beyond their control.
This guide explores what polyvagal theory is, how it may relate to trauma and mental health, and some practical approaches that people find helpful for supporting nervous system regulation.
What is polyvagal theory?
Polyvagal theory is a scientific framework that describes how the autonomic nervous system—the part of our nervous system that operates largely outside conscious awareness—responds to our environment and shapes our emotional and physical states.
The term “polyvagal” refers to the multiple (“poly”) branches of the vagus nerve, the longest cranial nerve in the body. The vagus nerve runs from the brainstem through the face, throat, heart, lungs, and digestive system, playing a central role in regulating many of our bodily functions.
Traditional understanding of the autonomic nervous system described two branches: the sympathetic nervous system (responsible for mobilising us into action) and the parasympathetic nervous system (responsible for rest and recovery). Porges’ contribution, first presented in his 1995 paper in Psychophysiology, was to identify that the parasympathetic system actually contains two distinct pathways, each with different evolutionary origins and functions.
This insight has significant implications for understanding human behaviour, particularly our responses to stress and threat. As described by the Polyvagal Institute, the theory conceptualises autonomic state as a neural platform influencing behavioural, physiological, and psychological responses.
The three states of the autonomic nervous system
According to polyvagal theory, our autonomic nervous system operates through three primary states, each associated with different physiological responses and subjective experiences. These states evolved sequentially over millions of years, with each representing a different survival strategy.
Ventral vagal state: safety and social connection
The ventral vagal state is associated with feelings of safety, calm, and social engagement. When we’re in this state, we tend to feel grounded, present, and capable of connecting with others.
Physiologically, the ventral vagal state is characterised by a regulated heart rate, steady breathing, relaxed facial muscles, and a calm digestive system. This state supports clear thinking, emotional regulation, and the ability to engage socially—what Porges calls the “social engagement system.”
The social engagement system involves the muscles of the face, middle ear, and larynx. When active, it allows us to make eye contact, modulate our voice, listen attentively, and express ourselves through facial expressions. These capacities are fundamental to human connection and communication.
From an evolutionary perspective, the ventral vagal pathway is the most recently evolved component of our autonomic nervous system. According to research published in PMC, it developed in mammals as a way to support the complex social bonds necessary for survival in group-living species.
Sympathetic state: mobilisation and action
When our nervous system detects potential threat, it may shift into a sympathetic state—commonly known as the “fight or flight” response. This mobilisation response prepares the body to take protective action.
In a sympathetic state, heart rate increases, breathing becomes faster and shallower, muscles tense in preparation for movement, and non-essential functions like digestion slow down. Subjectively, this state may be experienced as anxiety, panic, irritability, or restlessness.
The sympathetic response evolved as an essential survival mechanism. When faced with genuine danger, the ability to fight or flee can be life-saving. However, difficulties can arise when this response becomes activated in situations that aren’t actually dangerous, or when it remains chronically activated over time.
For people who have experienced trauma, the sympathetic state may be triggered more easily or by stimuli that remind them of past threatening experiences, even when no current threat exists.
Dorsal vagal state: immobilisation and shutdown
The oldest component of our autonomic nervous system is the dorsal vagal pathway. When the nervous system perceives overwhelming threat—particularly when fighting or fleeing seems impossible—it may shift into a dorsal vagal state of immobilisation.
This shutdown response involves a dramatic slowing of metabolic activity. Heart rate drops, breathing becomes shallow, and the body may feel heavy, numb, or disconnected. Subjectively, this state is often experienced as dissociation, depression, hopelessness, or a sense of being “frozen” or “collapsed.”
The dorsal vagal response is sometimes called the “freeze” response, though it’s important to distinguish this from the alert immobility that can occur in a sympathetic state (sometimes called “freeze with fear”). The dorsal vagal state involves a more complete metabolic shutdown.
In nature, this response can serve protective functions—playing dead, for instance, may deter some predators, and the numbing quality of this state may reduce suffering in inescapable situations. However, when this response becomes a default pattern in everyday life, it can significantly impact wellbeing and functioning.
Understanding neuroception: your body’s safety radar
One of the most clinically significant concepts within polyvagal theory is neuroception—a term Porges coined to describe how our nervous system continuously evaluates risk and safety in our environment, largely below the level of conscious awareness.
Unlike perception, which involves conscious recognition of stimuli, neuroception operates automatically and unconsciously. Our nervous system is constantly scanning for cues of safety and danger in our environment, in other people, and within our own bodies.
Neuroception influences which autonomic state we shift into. When neuroception detects safety, the ventral vagal system can remain engaged. When threat is detected, the nervous system may shift toward sympathetic activation or, if the threat seems overwhelming, dorsal vagal shutdown.
How trauma can affect neuroception
For people who have experienced trauma, neuroception may become calibrated toward threat detection in ways that were adaptive during the traumatic experience but less helpful afterward.
This can manifest as a nervous system that:
- Detects threat in situations that are actually safe
- Struggles to recognise genuine safety cues
- Responds to minor stressors as if they were major threats
- Remains in a chronic state of activation or shutdown
Understanding neuroception can be helpful because it explains why trauma responses often feel involuntary. When someone experiences anxiety, hypervigilance, or shutdown in situations that logically seem safe, it’s not a failure of willpower or rationality—it’s the nervous system responding to its own assessment of safety, based on past experience.
This understanding can reduce self-blame and open possibilities for working with the nervous system rather than against it.
The polyvagal ladder: a helpful metaphor
Many clinicians and educators use the metaphor of a “ladder” to help illustrate how we move between autonomic states. This concept, popularised by clinician Deb Dana, presents the three states as rungs on a ladder.
At the top of the ladder is the ventral vagal state—a place of safety and connection. In the middle is the sympathetic state—mobilised and ready for action. At the bottom is the dorsal vagal state—shutdown and withdrawn.
Throughout each day, we naturally move up and down this ladder in response to our experiences and environment. A sudden loud noise might briefly drop us into sympathetic activation; a warm interaction with a friend might help us climb back to ventral vagal engagement.
The goal isn’t to remain permanently at the top of the ladder—all states serve important functions. Rather, the aim is to develop flexibility in moving between states as appropriate, and to have reliable pathways back to ventral vagal safety after periods of activation or shutdown.
For people with trauma histories, the ladder may feel less like a ladder and more like a slippery slope, where small triggers can lead to rapid descent into sympathetic activation or dorsal vagal collapse, with difficulty climbing back up. Dana’s book The Polyvagal Theory in Therapy offers practical approaches for working with these patterns.
Polyvagal theory and trauma
Polyvagal theory has become particularly influential in trauma therapy because it offers a physiological framework for understanding trauma responses.
Trauma occurs when an experience overwhelms our capacity to cope, often involving intense fear, helplessness, or horror. During traumatic experiences, our nervous system mounts survival responses—fight, flight, or freeze—aimed at protecting us.
After trauma, the nervous system may remain in a state of heightened alert, continuing to respond as if danger is still present. This can manifest as the symptoms commonly associated with post-traumatic stress: hypervigilance, exaggerated startle responses, emotional reactivity, avoidance behaviours, and dissociation.
From a polyvagal perspective, these symptoms represent the nervous system’s ongoing attempts at protection, even when the original threat has passed. The body, in a sense, hasn’t yet received the message that it’s safe.
Complex trauma and polyvagal theory
Polyvagal theory may be particularly relevant for understanding complex trauma—trauma that is repeated, prolonged, or occurs within relationships, often beginning in childhood.
When early experiences involve chronic threat, neglect, or unpredictable caregiving, the developing nervous system may adapt in ways that prioritise survival over connection. Neuroception may become calibrated to expect danger rather than safety. The capacity for ventral vagal engagement may be underdeveloped.
This can result in patterns such as:
- Difficulty trusting others or forming secure attachments
- Chronic activation (anxiety, hypervigilance) or shutdown (depression, dissociation)
- Challenges with emotional regulation
- Difficulty feeling safe in one’s own body
Understanding these patterns as adaptations rather than pathology can be an important shift for many people. The nervous system was doing its best to survive difficult circumstances; healing involves helping it learn that those circumstances have changed.
Research published in Developmental Psychobiology explores how polyvagal theory provides organising principles for understanding the development of adaptive responses to traumatic stress.
The fawn response: an additional consideration
While Porges’ original polyvagal theory focused on fight, flight, and freeze responses, some clinicians have expanded this framework to include a fourth response: fawning.
The fawn response involves attempting to appease or please others as a way of avoiding conflict or harm. This might manifest as people-pleasing, difficulty saying no, prioritising others’ needs over one’s own, or losing touch with one’s own preferences and boundaries.
The fawn response can be understood as a relational survival strategy—particularly relevant when the source of threat is also someone upon whom one depends. For a child in an abusive or neglectful home, for instance, fighting or fleeing may not be viable options. Keeping the caregiver calm through compliance may represent the most available path to safety.
Like other trauma responses, fawning can persist long after it’s needed, showing up as chronic self-abandonment in adult relationships.
The window of tolerance and polyvagal theory
The concept of the “window of tolerance,” developed by psychiatrist Dr Dan Siegel, complements polyvagal theory and is often used alongside it in trauma therapy.
The window of tolerance describes the optimal zone of arousal within which a person can effectively manage stress and emotions. Within this window, we can think clearly, regulate our emotions, and respond flexibly to challenges.
When stress or triggers push us outside our window of tolerance, we may move into either hyperarousal (similar to sympathetic activation) or hypoarousal (similar to dorsal vagal shutdown). Research in the Journal of Psychopharmacology has explored how autonomic dysregulation relates to the window of tolerance model in complex trauma.
For people with trauma histories, the window of tolerance may be narrower, meaning they’re more easily pushed into states of hyper- or hypoarousal. Therapeutic work often involves gradually expanding this window while developing skills to return to the regulated zone.
How polyvagal theory relates to EMDR therapy
Eye Movement Desensitisation and Reprocessing (EMDR) is an evidence-based therapy for trauma that involves processing distressing memories while engaging in bilateral stimulation, typically through guided eye movements. In Australia, EMDR practitioners can be found through the EMDR Association of Australia (EMDRAA).
Polyvagal theory and EMDR can be understood as complementary approaches. While EMDR focuses on processing specific traumatic memories, polyvagal-informed approaches focus on the state of the nervous system more broadly. Rebecca Kase’s work on Polyvagal-Informed EMDR demonstrates how these approaches can be integrated.
Some ways these approaches may work together include:
Preparing the nervous system for processing: EMDR therapy typically begins with a preparation phase that includes developing resources for emotional regulation. From a polyvagal perspective, this can be understood as helping the client access ventral vagal states from which processing can occur more safely.
Understanding window of tolerance: The concept of the “window of tolerance”—the zone of arousal within which we can process information effectively—aligns with polyvagal concepts. Effective EMDR involves keeping activation within a range where processing can occur, neither too activated (sympathetic overwhelm) nor too shutdown (dorsal vagal dissociation).
Working with the body: Both approaches recognise that trauma is held not just in cognitions but in the body. EMDR includes attention to body sensations, and polyvagal-informed approaches emphasise working with the nervous system directly.
Supporting integration: After EMDR processing, polyvagal-informed practices may help integrate changes and support the nervous system in recognising new safety.
Practical approaches for nervous system regulation
While professional support is important for trauma recovery, there are also practices that many people find helpful for supporting day-to-day nervous system regulation. The following are some commonly suggested approaches.
It’s worth noting that what works varies significantly from person to person. Something that helps one person regulate may feel uncomfortable or even activating for another. Gentle experimentation and self-compassion are key.
Breathing practices
The breath is one of the few autonomic functions we can consciously influence, making it a potential pathway for affecting nervous system state.
Extended exhale breathing: Lengthening the exhale relative to the inhale may help activate the parasympathetic nervous system. Try inhaling for a count of four, then exhaling for a count of six or eight. Some people find it helpful to exhale through pursed lips or with a gentle sighing sound.
Physiological sigh: Research by Dr Andrew Huberman and others has examined a breathing pattern involving two quick inhales through the nose followed by a long exhale through the mouth. This pattern appears to help reduce stress relatively quickly for some people.
Vagal toning exercises
Several practices are thought to stimulate the vagus nerve directly, potentially supporting ventral vagal engagement.
Humming or singing: The vagus nerve passes through the muscles of the larynx, and vocalisation may help stimulate vagal tone. Some people find humming, singing, or even just making “voo” or “om” sounds to be calming.
Cold water exposure: Brief exposure to cold water—such as splashing cold water on the face or holding a cold pack to the face or chest—may activate the “dive reflex,” which involves vagal activation. This should be approached gently and may not be suitable for everyone.
Gargling: Vigorous gargling with water may stimulate the vagal pathways connected to the throat muscles.
Orienting and grounding
Practices that help bring attention to the present moment and immediate environment may help signal safety to the nervous system.
Orienting to the environment: Slowly looking around your space, allowing your eyes to rest on different objects, noticing colours, textures, and shapes. Some people find it helpful to name what they see silently or aloud.
Grounding through the body: Feeling the contact between your body and the floor or chair, noticing the temperature of the air, the texture of fabric against your skin, or other physical sensations that anchor you in the present.
The 5-4-3-2-1 technique: Naming five things you can see, four you can hear, three you can touch, two you can smell, and one you can taste. This engages multiple senses and directs attention outward.
Safe social connection
Given the central role of social connection in the ventral vagal system, genuine connection with safe others may be one of the most powerful regulators of the nervous system.
This might involve spending time with trusted friends or family, making eye contact with someone who feels safe, hearing a familiar and comforting voice, or simply being in the presence of others who feel regulated and grounded.
For people whose trauma occurred in relationships, social connection may also feel threatening. In these cases, working gradually toward connection, perhaps with the support of a therapist, can be an important part of healing.
Movement
Movement can be particularly helpful when the nervous system is in a sympathetic (mobilised) state, as it allows the body to complete the action sequence that the fight-or-flight response initiated.
This might include walking, running, dancing, shaking, or any form of movement that feels accessible. Some people find that allowing natural movements to emerge—shaking, trembling, stretching—can help discharge stored activation.
Slower, gentler movement practices like yoga, tai chi, or simple stretching may help when the goal is to transition from activation toward calm.
Is polyvagal theory evidence-based?
It’s important to address this question honestly, as scientific integrity matters, particularly in health-related content.
Polyvagal theory has been influential in clinical practice and has generated considerable research interest. The core concept that the vagus nerve has distinct branches with different functions is well-established anatomically. The idea that our autonomic nervous system responds to perceived safety and threat in ways that influence our behaviour is broadly consistent with our understanding of stress physiology.
However, some specific claims within polyvagal theory have been questioned by researchers. In a 2023 paper published in Biological Psychology, Paul Grossman raised concerns about aspects of the theory’s physiological premises. Critics have questioned elements of the evolutionary narrative, some proposed mechanisms, and whether all aspects of the theory are adequately supported by evidence.
Dr Porges has responded to these critiques through the Polyvagal Institute, and scientific dialogue on the topic continues. A 2025 paper in Clinical Neuropsychiatry provides Porges’ most recent response to criticisms and outlines the current status of the theory.
This is a normal part of how scientific theories develop and are refined over time. As noted in a balanced review in the Journal of Psychiatry Reform, the theory may be “scientifically questionable but useful in practice.”
From a clinical perspective, many practitioners find polyvagal theory to be a useful framework that helps clients understand their experiences and guides therapeutic interventions, even as the scientific details continue to be investigated. The practical applications—such as attending to safety, working with the body, and supporting co-regulation—have value regardless of whether every theoretical detail proves correct.
As with any framework, it’s helpful to hold polyvagal theory with appropriate nuance: useful for understanding and working with nervous system responses, while remaining open to evolving scientific understanding.
Working with a therapist
While self-help approaches can be valuable, working with a qualified mental health professional is often important, particularly for trauma recovery.
A therapist trained in trauma-informed and polyvagal-informed approaches can:
- Provide a safe relational context that supports nervous system regulation
- Help you understand your own patterns of activation and shutdown
- Guide you through practices tailored to your specific needs
- Support you in processing traumatic memories safely
- Help you develop greater nervous system flexibility over time
When seeking a therapist, you might look for someone with training in trauma-informed approaches such as EMDR, Somatic Experiencing, Sensorimotor Psychotherapy, or other modalities that attend to the nervous system.
In Australia, psychologists registered with AHPRA (the Australian Health Practitioner Regulation Agency) have met national standards for education and practice. You can verify a psychologist’s registration through the AHPRA website. The Psychology Board of Australia oversees registration requirements for the profession.
For EMDR-trained therapists specifically, the EMDR Association of Australia maintains a directory of accredited practitioners.
Supporting resources
If you’re experiencing distress, support is available:
- Lifeline Australia: 13 11 14 (24-hour crisis support)
- Beyond Blue: 1300 22 4636 (anxiety and depression support)
- 1800RESPECT: 1800 737 732 (sexual assault and domestic violence support)
- SANE Australia: 1800 187 263 (complex mental health support)
For Aboriginal and Torres Strait Islander peoples, 13YARN (13 92 76) offers culturally safe crisis support.
Frequently asked questions
What is polyvagal theory in simple terms?
Polyvagal theory is a way of understanding how your nervous system responds to safety and danger. It suggests that your body has three main states: one for feeling safe and social, one for action and defence, and one for shutdown when things feel overwhelming. Your nervous system moves between these states based on its assessment of your environment, often without your conscious awareness.
What are the three states of polyvagal theory?
The three states are: the ventral vagal state (associated with safety, calm, and social connection), the sympathetic state (associated with mobilisation, fight-or-flight, and high energy), and the dorsal vagal state (associated with shutdown, immobilisation, and conservation of energy).
How does polyvagal theory relate to trauma?
Polyvagal theory provides a framework for understanding why trauma can have lasting effects on the nervous system. Traumatic experiences can shift our nervous system toward chronic states of defence (either high activation or shutdown) and affect how we perceive safety and threat. Understanding this can help reduce self-blame and inform approaches to healing.
What is neuroception?
Neuroception is a term coined by Dr Stephen Porges to describe how our nervous system unconsciously evaluates safety and threat in our environment. Unlike conscious perception, neuroception happens automatically and influences which autonomic state we shift into. Trauma can affect neuroception, causing us to detect threat even in safe situations.
Can you control your nervous system state?
While autonomic nervous system responses are largely involuntary, there are practices that may help influence them. Breathing techniques, movement, grounding exercises, and safe social connection can all support nervous system regulation. However, this is typically a gradual process rather than an immediate switch, and professional support may be helpful.
Is polyvagal theory the same as fight, flight, freeze?
Polyvagal theory expands on the traditional fight-flight-freeze understanding by providing more detail about the physiological mechanisms involved and adding the dimension of social engagement. It distinguishes between two types of parasympathetic response (ventral and dorsal vagal) and emphasises the role of the social engagement system in regulation.
How long does it take to regulate the nervous system?
This varies significantly depending on individual factors, trauma history, and the approaches used. Moment-to-moment regulation (calming down after a stressor) can sometimes occur within minutes using breathing or grounding techniques. Longer-term changes to baseline nervous system patterns typically develop over months or years of consistent practice and, often, therapeutic support.
What kind of therapist works with polyvagal theory?
Many trauma-informed therapists incorporate polyvagal concepts into their work. Approaches that explicitly work with the nervous system include Somatic Experiencing, Sensorimotor Psychotherapy, and polyvagal-informed therapy. EMDR therapists may also integrate polyvagal understanding. When seeking a therapist, asking about their approach to working with the body and nervous system can be helpful.
Conclusion
Polyvagal theory offers a framework for understanding the intimate connection between our physiology and our emotional lives. For those navigating trauma, anxiety, or difficulties with regulation, it can provide both explanation and hope—explanation for why our bodies respond as they do, and hope that these patterns can shift.
The nervous system, though profoundly shaped by past experience, retains capacity for change throughout life. With appropriate support, understanding, and practice, it’s possible to develop greater flexibility in moving between autonomic states and more reliable access to feelings of safety and connection.
If the ideas in this article resonate with you, consider exploring them further with a qualified mental health professional who can help you apply them to your specific situation and needs.
This article is intended for educational purposes and does not constitute medical or psychological advice. If you are experiencing mental health difficulties, please consult a qualified health professional.