To this day, many medical professionals do not fully understand or appreciate the physical impact of trauma on the nervous system (and therefore, the entire body). Since the nervous system interacts with all other body systems, many possible physical symptoms can result. These symptoms will be different for everyone, since we all have our own unique bodies with our own unique nervous systems. Unfortunately, these symptoms frequently elude precise medical diagnosing. Since everyone who has been traumatized ends up with their own personalized collection of sequelae, the symptoms you report to
a medical professional may not match their criteria for specific medical disorders.
The way the brain generates the sensation of pain complicates this picture further. All pain is literally a sensation generated by your brain. Consider this example: Suppose you were hit over the head with a hammer; naturally, you would probably feel some pain. However, the hammer itself did not cause the sensation of pain; rather, your brain detected the assault caused by the hammer, and therefore emitted a pain signal to the body. The power of the brain to produce pain is even more amazing than that. Have you ever heard of phantom leg syndrome? Sometimes people with amputated limbs feel excruciating pain…in a limb that no longer exists (Stahl 2021)!
But what if your whole body is dysregulated? That’s precisely what happens with trauma. Since both branches of the nervous system are affected, and since the nervous system interacts with every other system, there are plenty of other areas in your body that will be off-kilter in one way or another. The brain detects anomalies within the body itself and generates pain signals the same as it would with a foreign object—such as a hammer (Stahl 2021).
But here’s the problem: If so many things are off in the body all at once, and these anomalies are so widely scattered, the brain cannot possibly generate precise pain signals for everything. Instead, you might feel diffuse, generalized pain throughout your whole body (that does not match the precise signs and symptoms your doctor is looking for), or your brain might even send pain signals for other parts of your body in which there is nothing medically wrong, sort of like the phantom limb we just talked about. But regardless, that pain is real. The pain is telling you that your nervous system has been assaulted—and that message is not wrong (Stahl 2021).
So what ultimately causes the nervous system to get stuck in some people but not in others? This is a wide-open question within the trauma field. There are many plausible explanations, but at this point, there does not seem to be one single definitive factor that determines why some people become traumatized and others do not. A particular event may trigger the reset for some people, but not for others. And some people may experience a reset after a single occurrence of an event, while other people experience the reset only after many recurrences. Still others experience the reset after many occurrences of many different events.
Regardless, this much is clear: trauma is not defined by the event itself, but rather by the effect it has on the person. If both the sympathetic and parasympathetic nervous systems become hijacked, then you were traumatized…period (Levine 2010). So far, you have learned about how trauma affects the nervous system in general. Sine the brain is literally the head of the nervous system, let’s zoom in on two tiny parts of the brain that play a monumental role in both the causes and effects of trauma: the amygdala and the thalamus.
The amygdala is the alarm system for the entire brain and therefore the rest of the body. The amygdala is associated with both fear and anger. Both emotions inform of us of risk or danger, whether perceived or real. Fear tells us something bad may happen, while anger tells us something bad already did happen. This is the information the SNS needs in order to mobilize its fight-or-flight response.
But here’s the deal with the amygdala: It is super good at remembering past threats. Therefore, anything that even remotely resembles a previous danger will fully activate the amygdala, which in turn reactivates all the other parts of the brain that were active during the prior danger (including sights, sounds, and smells). All of that launches a full mobilization of the fight-or-flight response, which may also trigger the freeze response…and now we are off to the races. This is exactly why trauma reminders are so triggering, sometimes resulting in rage, flashbacks, or fainting (Van der Kolk 2014).
The thalamus is the second tiny part of brain that plays a crucial role in trauma symptoms. The thalamus is the part of the brain that is responsible for integrating incoming sensory information (from all senses except for smell) and sending that data to other parts of the brain—including the amygdala—for further processing. When we are going through our normal daily routine in the absence of danger, the brain incessantly synthesizes a massive deluge of information. Once the information from the five senses (and other data points) are synthesized into a single, coherent message, that message is either regarded as relevant and stored in one of the memory folders, or disregarded as unimportant and quickly forgotten.
However, when we are presented with a threatening situation, for some reason the thalamus goes offline. The practical implications are enormous. When the thalamus is inactive, there is nothing to integrate all the incoming sensory information. That’s precisely why, after surviving a crisis situation, we remember only fragments of what happened rather than the incident in its entirety. For example, you may remember the gunshot (sound), the attacker’s face (sight), and the piercing pain in your foot (touch), but not the coherent, integrated sequence of what happened. So why is that a problem? Well, because the brain will file only complete, integrated memories into long-term memory—not memory fragments! That means many of the worst details of what happened are now stuck in your current ongoing awareness at all times. That explains the intrusive trauma memories of post-traumatic stress disorder (Van der Kolk 2014).
Here’s a simple example to illustrate these concepts: The sensory details of what happen to you all day long are like pieces to a puzzle. The job of the thalamus is to put the pieces together to form some sort of coherent picture. Once the puzzle is complete, the picture gets stored in long-term memory, where it can be later retrieved if necessary. But during a threatening situation, since the thalamus is not working the way it normally does, the pieces to the puzzle do not get assembled—which also means they do not get stored in long-term memory. These unprocessed memory fragments remain at the front of your mind—both day and night.
When you sleep, the brain continues to sort through all the cognitive, emotional, and sensory information received while you were awake, and to connect these data points to other memories you already have. Much of this work happens in your dreams. When you sleep, the brain turns into a puzzle-solving machine. In fact, the brain might be working on hundreds of puzzles at once, with pieces from all of them! Now do you see why dreams can seem so random and bizarre? In the same dream, you might have a scene with Michael Jordan, Abraham Lincoln, your high school crush, and your lost gerbil. What do these things have in common? Nothing! Your brain is simply conducting its never-ending mission of organizing, classifying, and filing the gazillion data points it receives. But there’s one glitch: it still does not know what to do with those pesky memory fragments from the traumatizing incident. These are the pieces that do not fit into any puzzle the mind is working on. And that’s why those details keep coming up over and over again in nightmares.
Post-traumatic stress disorder, or PTSD for short, effectively means the “trauma after the trauma.” This diagnosis should now make sense in light of everything you just read. When some sort of adverse event happens that is chronic or severe enough to hijack both branches of your nervous system, and the unprocessed memory fragments of what happened are forever present in the forefront of your mind (both day and night), and the amygdala randomly refires at the slightest trauma reminder…now you are traumatized.
Having your nervous system hijacked is now the new trauma. It is the trauma after the trauma—and in many senses, it is much worse than the original traumatizing event. Usually, the original event started but has ended (with the obvious exception of a current, ongoing threat). But a dysregulated nervous system just keeps going…In summary, the flight, flight, and freeze responses were all meant to be short-term solutions to an unexpected situation. But when one of these responses persists beyond its original usefulness, it’s like a hijacked Uber careening down the highway, causing one collision after another.
