What is Trauma?

Trauma is the physiological response to any event or series of events that we perceive as life threatening and that overwhelm us. As the nervous system operates as an all-or-nothing system, the event doesn’t need to be life threatening. It only needs to be perceived as such.

Trauma happens as a result of our nervous system not having the chance to orient and respond appropriately to a perceived threat. That threat can be internal or external.  Trauma resides in the nervous system and happens to all of us. It is important to note that trauma is cumulative. Its impacts accumulate in the nervous system. Trauma brings on an experience of loss of autonomy and loss of sense of agency.

Categorizing trauma into four distinct types can offer a comprehensive understanding of its various forms.

These categories include:


Impact trauma

This category encompasses events such as falls or motor vehicle accidents. These incidents involve a physical force that directly impacts an individual, potentially causing injury or harm.


Medical and dental trauma

Medical trauma refers to any procedure that is perceived as overwhelming by the patient. For instance, the experience of general anesthesia is considered traumatic, as it involves entering a state of near-death. Dental procedures, especially those inducing anxiety or fear, can also fall under this category.


Relational trauma

Relational trauma is a widely recognized form of trauma that involves disruptions in relationships. An example is the Adverse Childhood Experiences (ACEs), which are traumatic events occurring in childhood and significantly affecting the individual’s well-being.


Other trauma

This category encompasses diverse events such as near drowning or being electrocuted. These incidents may not fit neatly into the previous three categories but are equally impactful traumatic experiences.

Understanding these four distinct categories provides a framework for comprehending the various facets of trauma, each with its unique characteristics and consequences.

The Polyvegal Theory and how
it relates to patient trauma.

Dr. Stephen W. Porges, a distinguished figure from the National Institute of Health and the National Institute for the Clinical Application of Behavioral Medicine, has made groundbreaking contributions to the field through the development of the Polyvagal Theory. Widely embraced in the realms of Psychology and Clinical Counseling, this theory serves as a pivotal tool in unraveling the intricacies of the nervous system’s response to traumatic events and their enduring impact.

The Polyvagal Theory simplifies the understanding of the autonomous nervous system by delineating it into three distinct states:


social engagement,


fight/flight response,


and freeze response.

In terms of its physiological components, these states correspond to the:


ventral vagal,


sympathetic arousal,


and dorsal vagal systems.

The ventral vagal system plays a crucial role in facilitating social engagement without triggering the fight or flight response.

Ideally developing in the first year of life through interactions with primary caregivers, this system becomes inhibited in cases of trauma. Subsequently, the survival systems of sympathetic arousal or dorsal vagal take precedence.

The sympathetic system activates the well-known fight or flight response, preparing the body for rapid action. Conversely, if there’s a perceived inability to overcome the threat, the dorsal vagal system intervenes, inducing the freeze response—an instinctive reaction akin to feigning death.

Image used with permission from NICABM

Trauma and the brain.

 We can look at the brain in a very simplistic way as having 3 main parts:
rational thinking brain, emotional brain and survival brain.

When our nervous system is in social engagement, we have access to the whole brain. When our nervous system is in survival, fight/flight response or freeze response, we lose access to our rational thinking brain and operate from the more primitive part of our brain.

We can metaphorically think about the nervous system as a container holding unresolved trauma. We all have a container of trauma. For some there are not a lot of experiences filling the container. The world feels like a safe and comfortable place.  However, for others, there are many experiences in the container. There is only a little room left in it. As a result, their nervous system will be in flight/flight or freeze response more easily.

 To give you an example of how any dental experience can be experienced as traumatic by the nervous system, especially if I have a full trauma container. From the perspective of the rational brain, I am laying down in the treatment chair next to the OHP. I am aware that the OHP will be using dental tools in my mouth. I am there willingly because I know that it’s good for me. If my trauma container sends me into survival mode, it can very easily be experienced as I am in a very vulnerable position, where I can’t easily protect or defend myself, next to a stranger who puts tools in my mouth. Keep in mind that this survival experience, most of the time, is subconscious for the patient.

Lying down in a supine position places us in a very vulnerable position. It is difficult to defend oneself from a supine position. Having objects placed in our mouth and not being able to close our mouth to protect oneself also goes against survival response. And to add to the mix, many people who experienced impact trauma or relational trauma may have boundary ruptures. A boundary rupture is a disruption of the neuroception which makes a space in that area being read as unsafe by the nervous system. (Consider revise the wording). And often, the OHP has to sit right in the boundary rupture area in order to do their work. It makes it even more difficult for the patient to be regulated.

Are you wanting to apply this information to create a trauma-informed clinic?

Do you have a question?