Trauma affects every part of the body and every part of the brain. That’s a lot of turf. There is still much that even highly trained professionals do not understand about how trauma affects a person, both physically and emotionally. What follows is an introduction to the causes and effects of trauma.
How is it possible for trauma to affect the entire body and the entire brain? At its core, trauma is a disorder of the nervous system. And since the nervous system is the bridge between the brain and the rest of the body, anything that assaults the nervous system will affect everything else.
More specifically, trauma directly assaults the autonomic nervous system (ANS), which is just the fancy medical way of saying the branch of the nervous system that operates automatically (whether we are thinking about it or not). This system regulates everything we do unconsciously, ranging from breathing to digesting to pumping blood. Within the ANS, there are two branches, or subsystems: the sympathetic nervous system (SNS) and the parasympathetic nervous system
(PNS). Imagine these two branches as parts of a car: the SNS works like an accelerator, while the PNS operates like a brake.
Sometimes the sympathetic branch is referred to as the fight-or- flight system, while the parasympathetic branch is referred to as the rest-and-digest system. Depending on what is going on in the body or environment, sometimes the nervous system applies the brake, and sometimes it steps on the gas. Just like a car, the body needs both functions.
The PNS is also related to social interactions. When we trust someone and feel at ease in their presence, we feel warmth, empathy, and connection. We might even smile or laugh. This is a sign that the rest-and-digest system is currently activated. It is no wonder that in cultures all around the world, eating is a highly social event, especially during times of celebration. The system we use to digest food is also the system we use to connect with other people. But when we do not trust someone, we feel tense and on edge, poised to react at a moment’s notice (Porges and Porges 2023). That’s the fight-or-flight system.
We have all heard of fight or flight, but the nervous system actually has three basic instinctual responses to danger or crisis: fight, flight, and freeze. All of these responses are prevalent throughout the animal kingdom. In fact, many animals have a preferred default response. For example, bears fight, bunnies flee, and possums freeze. Humans, with all our sophistication, do all three. (In fact, humans even have a fourth trauma response—called fawning—that will be explained in a later chapter).
When humans are presented with danger, the first thing to happen is that the social part of the PNS—the car’s brake—goes
offline. In the face of a threat, we have no need for warmth, empathy, or connection. On the contrary, we need to be super alert and ready at a moment’s notice to disconnect by either fighting or fleeing. In other words, the first thing our nervous system does when faced with danger is take our foot off the brake.
However, if the danger persists, then the SNS takes over. Remember, the sympathetic branch is the car’s accelerator. This is the part of the nervous system that both energizes and mobilizes us to either fight or flee. This system is powered by the well-known body chemical adrenalin.
Whereas many animals have a set, preprogrammed default to either fight or flee, humans are endowed with many more brain cells, and therefore, we are equipped to make split-second choices between these options. In some cases, you will decide you have the strength and power to fight off the danger. In others, you will decide you are no match for the threat, and therefore, a mad dash would be a better use of adrenaline. Both fighting and fleeing are like slamming on the accelerator. Even though they may seem like opposite responses, fight and flight are very similar—both responses require superhuman surges of energy.
But what happens if you can neither fight off the threat nor flee the danger? Now what? Remember, we have both an accelerator and a brake. Just like we need both to drive, we also need both to survive. If you cannot avoid an accident by accelerating, then another option is to slam on the brakes. That’s what the PNS does, and that’s how you end up with the freeze response.
The freeze response includes many possible reactions, such as muscle paralysis, collapsing, fainting, or losing consciousness. Another common freeze reaction is dissociation. That’s when you start to mentally disengage from the event. The situation may seem unreal, or like it is happening to a different person. For example, you might view the entire situation playing out from the perspective of a third-party observer. Or you may enter an alternate, imaginary reality (Van der Kolk 2014).
The practical benefits of the freeze response are simple: If you cannot effectively deal with a threat by either fighting it or fleeing it (in other words, you are stuck with the danger), then you might as well conserve your energy, minimize the pain, and contain the amount of physical damage done to your body. For example, a tense body experiences much more damage than a relaxed or limp body (Levine 2010), which is precisely why drunk drivers often survive their lethal car crashes, whereas their victims do not.
But here’s the deal. If fight and flight work, you are much less likely to be traumatized, for two main reasons: First, because you were able to successfully deal with the threat by either fighting or fleeing. Second, because in the execution of fight and flight, you burned off all the extra energy produced by adrenaline (Levine 2010).
Yes, you will be rattled. Yes, your life may flash before your eyes. Yes, your heart may be pounding, your mind may be racing, and your lungs may feel like they are about to explode. But all of that will settle down as the adrenaline wears off and your SNS (the accelerator) is no longer glued to the floor. If anything, after the dust has settled, you will feel even stronger, even more empowered, and even more resilient than ever before. You faced the dragon…and lived to tell the tale!
But as soon as fight-or-flight responses are not viable options, and the freeze response kicks in, you are now much more at risk for becoming traumatized, for several reasons. First, the SNS is still active. All of the adrenaline, all of that fight-or-flight energy, is still cranking through your body; you are still “pedal to the metal.” The main difference is that now the PNS (the brake) has also been activated to counteract this. In other words, the freeze response is not just the brake—it is both the brake and the gas at the same time (Levine 2010). You can imagine what that would do to a car. This is also not a good long-term strategy for the human mind or body!
In addition, the freeze response (although highly adaptive as a short-term, last-ditch effort) comes at a steep psychological cost. For example, people who survive the freeze response often experience intense feelings of guilt, shame, and self-blame. They often wonder, Why didn’t I fight more? Why didn’t I try to escape? The reality is—they couldn’t!
And that’s precisely why the freeze response automatically kicks in. This is not a conscious decision. In fact, once the freeze response is active, you are now less able to fight or flee, since the body literally becomes limp or even paralyzed. Furthermore, people who experience dissociation as part of their freeze response learn to quickly disengage from other aspects of their life as well. In short, many of the psychological effects of trauma come from this freeze response (Levine 2010).
However, just because you experience a freeze response does not mean you were or will be traumatized; it simply means that you are now at risk. If the body does its thing with both the accelerator and the brake, they are no longer glued to the floor, and both branches of the nervous system return to their normal functioning, then most likely you will rebound after some time—rattled for sure, but nonetheless better, stronger, and wiser.
Trauma happens when both the sympathetic and parasympathetic branches experience a permanent (or long-term) reset. Both systems get hijacked, and they stay hijacked, sort of like stomping on both the accelerator and brake at the same time. This results in a war between the two branches that can last for years or decades, or even a lifetime. The more the sympathetic branch steps on the gas, pumps adrenaline through the body, and ramps up all body systems for fight or flight, the more the parasympathetic branch slams on the brakes, attempts to shut it all down, and tries to freeze all this extra arousal (Levine 2010).
In fact, part of what gets “frozen” in the freeze response is this excess adrenaline. Since the adrenaline energy was never allowed to get fully released through the default fight-or-flight responses, and yet it continues to be produced, it remains stuck within the body, causing all manner of physical problems. This power struggle between the SNS and PNS drains the entire brain and body of much needed resources, all while the casualties continue to mount. Who is impacted by a war? Everyone! Therefore, all body systems are affected by the collateral damage (Levine 2010).
Since the nervous system regulates (or at least influences) every other system of the body, the effects of unresolved trauma can be catastrophic, including a myriad of medical issues. In fact, think of it this way: trauma is a medical problem. In my opinion, trauma is best conceptualized as primarily a medical disorder with mental health implications, rather than the other way around. Trauma is not a problem in the head that also affects the body. Rather, it is a problem in the body that affects all aspects of the body, including the brain.
