Sympathetic vs. Parasympathetic Nervous System: What Does “Nervous System Regulation” Actually Mean?
If you've spent any amount of time in the wellness world lately, you've probably heard people talking about “regulating your nervous system.” We're being told to stimulate our vagus nerve, get out of fight-or-flight, practice breathwork, take cold showers, meditate, spend time outside, hum, shake, stretch, ground and do all kinds of things in the name of becoming more “regulated.”
And while many of those practices can absolutely be helpful, I think somewhere along the way we've taken a really complex and fascinating part of human physiology and oversimplified it. We've almost created this idea that your sympathetic nervous system is the bad guy, your parasympathetic nervous system is the good guy, and the ultimate goal of wellness is to somehow stay calm and parasympathetic all day long.
That's not actually how your nervous system was designed to work.
Your sympathetic nervous system is incredibly important. Your parasympathetic nervous system is incredibly important. You need BOTH, and a healthy nervous system should be able to move between them depending on what your body needs in that particular moment.
When I talk to patients at Flourish about nervous system regulation, I'm not talking about being perfectly calm all the time. I'm much more interested in something else: adaptability.
Can your nervous system appropriately rise to meet a demand when life requires more from you, and then shift gears when that demand has passed so your body can rest, digest, recover and restore?
That's the conversation I think we should be having.
The Quick Answer
What Does "Nervous System Regulation" Actually Mean?Nervous system regulation is not about staying parasympathetic or perfectly calm all day. Your sympathetic and parasympathetic nervous systems are both necessary. What matters is adaptability: your body's ability to appropriately rise to meet a demand and then shift toward rest, digestion, recovery and restoration when that demand has passed. |
First, What Is the Autonomic Nervous System?
Your nervous system is constantly gathering information about what's happening both inside and outside of your body and helping you respond appropriately, and much of that work happens without you ever consciously thinking about it. You don't have to remind your heart to beat while you're reading this article. You don't consciously tell your digestive system what to do after lunch, manually adjust your blood vessels when you stand up, or instruct your pupils to respond when you walk outside into bright sunlight.
Your body handles an enormous amount of information automatically, and your autonomic nervous system plays an important role in regulating many of those involuntary processes. It helps influence things like heart rate, blood pressure, digestion, breathing patterns, temperature regulation and many other functions happening behind the scenes throughout your day.
There are different components within the autonomic nervous system, but the two branches you'll hear us talk about most often at Flourish are the sympathetic nervous system and the parasympathetic nervous system. They have different roles, but they aren't competing against each other. They're both necessary parts of your body's ability to respond to its environment.
Your Sympathetic Nervous System Isn't the Enemy
Most people have heard the sympathetic nervous system described as the “fight-or-flight” system, and that's certainly one of its roles. If a car suddenly pulled out in front of you and you needed to slam on the brakes, your sympathetic nervous system would help mobilize your body very quickly so you could respond.
But sympathetic activity isn't reserved for emergencies. You use this part of your nervous system when you're exercising, giving a presentation, rushing to get somewhere on time, solving a difficult problem, competing in a sport, responding to your child calling for you or simply trying to focus and accomplish something during a busy day. It helps increase alertness and prepares your body to meet whatever demand is in front of you.
That's not unhealthy. In fact, it's necessary.
I think this distinction is really important because we've started using phrases like “fight-or-flight” almost as if sympathetic activation itself means something has gone wrong. Your body is SUPPOSED to be able to activate when it needs to. I want your nervous system to recognize when something requires more from you, mobilize the resources you need and help you respond appropriately.
The bigger question is what happens after the demand is over. Can your body recognize that the stressful moment has passed and shift gears, or does it seem to have a harder time settling back down?
So What Does the Parasympathetic Nervous System Do?
Your parasympathetic nervous system supports the other side of that equation. You'll often hear it called your “rest-and-digest” system because parasympathetic activity is associated with processes such as rest, digestion, recovery and restoration.
Think about what happens after you've finished dinner and you're relaxing on the couch, or when you're winding down before bed after a long day. Your body doesn't need to be prepared to sprint, solve a crisis or perform at its highest level in that moment, so resources can be directed toward processes associated with recovery and maintenance.
We absolutely want your nervous system to be able to access that state, but we don't want to live there 24 hours a day either. If you're peacefully driving home after a massage and someone runs a red light directly in front of you, I would very much like your nervous system to temporarily stop “resting and digesting” and help you hit the brakes.
That's why I think the popular “sympathetic = bad, parasympathetic = good” explanation misses the bigger picture. Neither one is inherently good or bad. The magic is in your body's ability to appropriately use both.
Nervous System Regulation Is Really About Adaptability
When I talk about nervous system regulation at Flourish, what I'm really interested in is how well your nervous system can adapt to what's being asked of it.
One of the easiest ways to think about this is like driving a car. You need an accelerator because sometimes you need to speed up, merge into traffic or climb a hill. You also need a brake because sometimes you need to slow down or stop. Neither pedal is better than the other. What matters is your ability to use the appropriate one at the appropriate time.
Your nervous system works in a much more sophisticated way than a gas pedal and a brake, of course, but the analogy helps us understand the larger idea. We don't want your body stuck with the accelerator pressed to the floor, but we also don't want you sitting on the brake while life is asking you to perform.
We want flexibility. We want your nervous system to respond when it needs to respond and recover when it has the opportunity to recover. That ability to shift appropriately is much closer to what nervous system regulation actually means.
Stress Isn't Only the Stuff That Feels Stressful
This is where the conversation becomes especially relevant to everyday life because when I ask patients whether they're stressed, sometimes the immediate answer is, “Honestly, I'm really not that stressed.”
Then we start talking.
Maybe they're sleeping six hours a night, drinking coffee before breakfast, working full time, raising kids, squeezing workouts into an already packed schedule, answering emails at 9:30 at night and wondering why their body doesn't feel particularly relaxed. They may not feel emotionally overwhelmed, but their body is still navigating a tremendous number of demands every single day.
Stress isn't only an emotion. Your nervous system is constantly responding to physical, chemical and emotional stressors, and not all of them are necessarily bad. A hard workout is a stressor. A demanding workday is a stressor. Poor sleep can place additional stress on the body. An illness is a stressor. Not eating enough can be a stressor. A major life transition can be stressful, and yes, worrying about something can certainly create stress too.
The goal isn't to create a life completely devoid of stress. That isn't realistic, and your body was designed to handle challenges. What I care much more about is the total load your body is navigating and how well you're adapting to it.
What Can a Nervous System That's Struggling to Adapt Feel Like?
This is another area where social media tends to oversimplify things because almost any symptom can now be labeled “nervous system dysregulation.” Poor sleep? Dysregulated nervous system. Headaches? Dysregulated nervous system. Digestive issues? Dysregulated nervous system. Fatigue? Dysregulated nervous system.
Real physiology is more nuanced than that.
Someone who is struggling with sleep, muscle tension, headaches, digestive changes, fatigue, irritability, feeling wired-but-tired or having difficulty relaxing may absolutely have nervous-system stress worth investigating, but those symptoms can occur for many different reasons. No single symptom automatically tells me exactly what your nervous system is doing or why you're experiencing it.
Your symptoms are important because they're part of your story, but symptoms alone don't always give us the entire answer. That's why, at Flourish, I want to know how you're feeling AND gather objective information about how you're functioning, whenever we have the ability to do so.
Can We Actually Measure How Your Nervous System Is Adapting?
One of the tools we use in our Allison Park chiropractic office is the CLA INSiGHT Spinal & Nervous System Scan. There are three different components to the scan, and one of them is called NeuroPULSE, which evaluates heart rate variability, commonly called HRV.
Heart rate variability looks at the subtle differences in time between individual heartbeats. If your heart rate is 60 beats per minute, for example, that doesn't necessarily mean your heart beats exactly once every second like a metronome. There are tiny variations in the amount of time between one heartbeat and the next, and those variations are influenced in part by your autonomic nervous system.
That's what makes HRV so interesting. It can provide us with another piece of objective information about patterns in autonomic nervous-system function and stress adaptability.
I want to emphasize the phrase “another piece of information” because I don't look at one HRV measurement and pretend it tells me everything happening inside your body. NeuroPULSE doesn't independently diagnose nervous-system dysfunction, and one number doesn't explain your entire health picture. We interpret that information alongside your health history, symptoms, examination findings, the other components of your Spinal & Nervous System Scan and, importantly, how those findings change over time.
Is a Higher HRV Always Better?
Not necessarily, and this is another place where I think the wellness industry sometimes turns complicated physiology into a number everyone feels like they should be chasing.
Heart rate variability can be influenced by age, fitness, sleep, illness, alcohol, medications, exercise, stress, breathing patterns and many other factors. Different wearable devices and measurement methods can also calculate and report HRV differently, which means comparing your smartwatch number directly to your spouse's or your friend's isn't particularly useful.
Context matters.
Rather than becoming obsessed with whether your HRV is “good” or “bad,” I'm much more interested in what the information means within the context of you. What does your baseline look like? What else is happening with your health? How are you feeling? What are the other components of your scan showing? And when we reassess later, what has changed?
That's one of the reasons I love having objective technology available in practice. It doesn't replace listening to the patient or using clinical judgment. It gives us additional information to put alongside everything else we already know.
Why We Repeat Spinal & Nervous System Scans at Flourish
If you've been a chiropractic patient at Flourish for a while, you know we periodically repeat your Spinal & Nervous System Scans throughout care, and there's an important reason for that.
I don't only want to know whether you feel better on a particular Tuesday afternoon. I want to understand how you're functioning and how things are changing over time.
One isolated measurement gives us a snapshot, while repeated measurements give us the opportunity to look for patterns. We can compare how you're feeling, how you're functioning, what has changed, what hasn't changed and what the objective information is showing us along the way.
Pain and symptoms absolutely matter, but wellness is bigger than whether your neck happens to hurt today. That's why reassessment is such an important part of the way we approach chiropractic care at Flourish.
Where Does Chiropractic Fit Into This Conversation?
Your spine and nervous system are closely connected, and your spinal joints contain sensory receptors that continuously provide your brain with information about movement and position. Chiropractic adjustments create sensory input into that system, which is one reason I'm interested in much more than simply chasing the location where someone hurts.
At Flourish, nervous-system-focused chiropractic care means we're considering how your spine is moving, what you're experiencing, what we're finding during your examination and scans, and how your body is responding over time. We're looking at the person as a whole rather than reducing chiropractic care to “my neck hurts, so adjust my neck.”
That also doesn't mean I'm going to tell you that a chiropractic adjustment magically removes stress from your life. I cannot adjust away your work deadline, make your toddler sleep through the night or, unfortunately, adjust your inbox down to zero. 😂
What we CAN do is evaluate your spinal and nervous-system function, provide appropriate chiropractic care and continue reassessing how you're responding. To me, that's a much more meaningful and realistic conversation about what nervous-system-focused chiropractic care actually looks like.
Chiropractic Isn't the Only Thing That Matters
As much as I love chiropractic, your nervous system is responding to your entire life, which means what you do outside of Flourish matters too.
Sleep matters. Adequate nutrition matters. Movement matters, and so does allowing yourself to recover from that movement. Time outside, healthy relationships, social connection, breathing, rest and creating moments in your day when your brain isn't receiving constant stimulation can all be meaningful pieces of the bigger picture.
Practices like meditation, breathwork, yoga and other relaxation strategies can certainly be useful tools for some people too. I just don't want nervous-system regulation to become another full-time job where you feel like you need a 17-step morning routine before your body is allowed to function normally.
Sometimes the answer isn't another wellness hack. Sometimes your nervous system needs you to stop scrolling and go to bed.
Your Calendar Says Cozy Season. Does Your Nervous System Agree?
October has a way of looking incredibly peaceful on Pinterest. There are cozy sweaters, candles, pumpkin spice, crisp mornings and blankets everywhere, while your actual calendar may be telling a completely different story.
That's part of the reason our Pumpkin Spice + Parasympathetic sweatshirts make me laugh. They're cute, they're a little nerdy and they're very Flourish, but there's also an important message hiding underneath the pumpkin spice.
Your body needs to be able to respond to life, and it also needs opportunities to recover from it. We don't need to eliminate sympathetic activity, and we don't need to spend every waking moment trying to become more parasympathetic. We need a nervous system that's capable of adapting to what's happening around us.
So the next time you hear someone talk about “regulating your nervous system,” I want you to think beyond simply becoming calmer. Think adaptability! Can your nervous system rise to meet a demand when it needs to and shift toward recovery when the demand has passed?
And if you've never actually looked at how your nervous system is functioning, that's one of the reasons we use tools like the CLA INSiGHT Spinal & Nervous System Scan at Flourish Wellness Practice. Because when it comes to your health, I would much rather gather information, understand the bigger picture and make thoughtful decisions from there.
Test... Don't guess.
In health & happiness,
Dr. Kate
Sympathetic vs. Parasympathetic Nervous System
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