Heart Rate Variable (HRV) and the Vagus Nerve’s Role In Trauma
“No wonder I can’t get anything done,” I thought, recovering in bed from the most recent panic attack that left me panting and exhausted. Everyone tells me to “just get over it,” but that feels impossible when your body is reeling in panic. I’ve read The Body Keeps the Score (Dr. Bessel van der Kolk), so I understand – trauma lives in the body, not the brain, and mine is in overdrive, remembering my past and reeling me into panic. My body grips in various places, often hurting me, and as the memory comes on, my breathing becomes jagged until it stops altogether. Pure panic, my little girl part is so scared, and my body remembers. “What does a panic attack or flashback do to my body?” I thought this one day, exhausted after only a few hours awake, due to recurring flashbacks.
I wondered, what’s really going on inside my traumatized body? If I understood it, maybe I could help it more.
Stephen Porges, PhD, defined Polyvagal Theory and the role the Vagus Nerve plays in regulating our health and behavior. (1) Finally, we understand the physiological and psychological states of our bodies. Dr. Porges explains the nervous system and how our bodies are Relaxed, Immobilized, or Mobilized.
For anyone with PTSD or CPTSD, we know that panic attacks, or flashbacks, can cause an increased heart rate, jagged breathing, and even pauses/freezes in breathing. We certainly fall into the “Mobilized” category when fearful or stressful emotions appear. And it’s the Vagus Nerve, the longest cranial nerve in your body, that decides that it’s time for rest/relaxation, and if danger is perceived, no way it’s going to rest. This is your nervous system reacting as it was built to protect you. It’s getting ready to do whatever is needed to keep you safe.
the vagus nerve
But it’s nice to know, finally, that you can literally not “get over it”. Turns out the Vagus Nerve decides the state of your body. (2) You literally cannot think your way out of it. Here it is, proof that it actually was not your fault!
We now understand that the body keeps the score, holding on to your unresolved emotions and storing them inside the fascia of your muscles. (3) Triggers appear and remind your body of the trauma, and suddenly, there’s lots of activation inside the body: increased/jagged breathing, sweating, tension in your muscles or entire body.
But how can I know the state of my Vagus Nerve?
I thought I was in a relaxed state, but after years of ignoring my trauma, I was actually very disconnected from my physical body. Fight/flight can become the standard you live with, not realizing how much stress your body is still under. There is a measurement that gives us an understanding of the Vagus Nerve’s ability to return to rest: the Heart Rate Variable. It turns out that your smartwatch tracks your heart rate and can tell you your
Heart Rate Variability (HRV), a guide to the state of your Vagus Nerve.
The measurement of your HRV tells you the likely state: a high HRV signals a nervous system able to return to rest easily; a low HRV often means that your body is fighting something and can leave you weak, drained of energy.
HRV varies constantly: it’s the measure of the time between your heartbeats. For years, we thought the heart at rest was like a metronome, faithfully beating in a regular, steady rhythm. Scientists and physicians now understand that this is far from the case.(4) Instead, there’s a lot of variation in how your heart beats. It makes sense. You know your heart rate increases when you work out or have sex. What happens when you have a PTSD memory or panic attack? Anyone who’s had one knows: your heart starts racing, draining you. Often, it takes a few hours to a few days to recover. (Yes, sometimes a few days.) The heart doesn’t beat to a monotonous tune; instead, it’s constantly changing and very irregular based on what you are experiencing. And with complex PTSD (or PTSD), your experience is interrupted by past dangers, over and over again, when you have a flashback or panic attack.
A higher HRV score is better, indicating resilience to stress and greater heart health, while a lower HRV may suggest stress/anxiety.
When your score is higher, your nervous system can respond quickly and effectively and switch back to rest and digest. Women typically experience more HRV fluctuation due to cycle phases. Trauma survivors often have lower, more unstable HRV until regulation practices begin.
https://www.heartmath.com/science/#
Research at the Heart Math Institute (5) supports this: emotional stress can give rise to irregular and erratic heart rhythm patterns. In fact, one of the most powerful factors affecting our hearts’ changing rhythm: our feelings and emotions. Anyone with PTSD can understand this:
When I panic, I tend to hold my breath, breathe irregularly, or stop/pause my breathing. So, of course, that affects my heart rate variable.
I had my answer: here’s what happens to the body when you have a panic attack, anxiety attack, or flashback: your heart races, maybe you pant and hold your breath, or stop breathing. Suddenly, your Vagus Nerve thinks you are in danger and sends your nervous system into fight/flight. Your heart rate variable (HRV) drops since the body is using a lot of energy to protect you.
How can I measure my HRV?
It’s challenging to measure manually, as it requires understanding the variation in time between heartbeats, which is constantly changing. If you have a Smart Watch or fitness tracker, you can see your HRV in the Health App (look for the Heart):
It becomes clear that the trend matters more than any one measurement; you can see how my HRV varies over time, sometimes completely different in a matter of hours. It’s important to look at the entire picture, and this is a guide to learn more about yourself and tune into your body – that’s where the trauma lives. So when I’m low (for me, 20s), I try to feel what’s going on in my body rather than ignoring the symptoms. Trauma is exhausting and follows us for years. We can’t ignore it. We need to normalize what it does to our bodies so we can support the physical body to release old traumas, not carry them indefinitely.
Ok, how do we fix this? How can we change the state of our bodies and get them to know safety after experiencing repeated trauma? How can we tell the Vagus Nerve, responsible for putting me in rest/digest, that it was time to go there? “Get back to rest, now, Vagus Nerve!” Well, it turns out that ordering it there will definitely not work (despite the advice of your childhood). The Vagus Nerve is onto you, and it’s not going into rest/relax until it’s absolutely sure there is no danger.
The first step is awareness: HRV can vary dramatically between individuals, so your trends are more important than comparing to others. When you have a low score, how do you feel? How about when it’s high, after a good rest? Can you tell the difference without seeing the score?
7 Things that Can Improve Your HRV:
- Awareness: treat yourself differently when you see a low HRV!
- Breathwork: practice with the HeartMath Institute - Scientifically validated techniques that help you learn coherence, and research proving the credibility of heart coherence. (Learn more about HeartMath here.)
- Boundaries. Stress, trauma, illness, sleep, alcohol, and hormones can shift HRV significantly.
- Vagus nerve stimulation – activates the parasympathetic nervous system (Learn more about Vagus Nerve Stimulators at the Good Girl Trauma Shop.)
- Sleep: Regular sleep is essential, and naps are allowed!
- Exercise: regular exercise, or even just stretching and moving, helps the physical body.
- Safe Connection/co-regulation.
What should my HRV be?
This is tough to answer, since we don’t have a huge set of data – yet. Here are three data points to reference:
1. Oura, the popular fitness tracker that uses a ring, has sold over 2.5 million rings. Oura reports an average HRV of 41 across all members: 41.5 ms for females and 40.3 for males. (6)
https://ouraring.com/blog/heart-rate-variability/
2. WHOOP is a wearable fitness tracker that has approximately 200,000 subscribers and shows the following ranges of HRV per their users: (7)
https://www.whoop.com/us/en/thelocker/normal-hrv-range-age-gender/
3. The largest research of Heart Rate Variability averages/scores was completed by the Lifelines Cohort study in the Netherlands (8), which captured HRV ratings from more than 153,000 people. Here are the median–middle ratings from that study, by Gender:
Median rMSSD per the Netherlands study of over 153K people
https://pmc.ncbi.nlm.nih.gov/articles/PMC7734556/?utm_source=chatgpt.com