What the hell even IS the nervous system?

...and how does it relate to pelvic pain, leaking, prolapse sensation, and literally every other pelvic floor condition?

Hello! Welcome to 2025. Here we are.

There’s a lot going on in my world this year — namely, I am (hopefully, fingers crossed) doing a big move at the end of the year. My husband is finishing his PhD and applying for academic jobs, and we are looking at Arizona and the west coast, but it’s anyone’s game right now. TBA!

On Friday, a long time client told me, “Okay, you’ve been hinting left and right about big changes. What ARE they!?”

And here it is: in 2025, I’ll be shifting my focus [even more] to the nervous system. Longish version: My private practice will move more towards a combination of pain reprocessing therapy and somatic integration work for folks with chronic pelvic pain, and my writing will likely reflect that. Shortish version/additionally: I’ll be shifting away from classic pelvic floor therapy and more into a whole body mental health support for people with chronic pain.

I’ll continue to write about all matters pelvic health, including specific diagnoses and movement. And really, the nervous system has been my lens for a long time, so I’m honestly not sure how much will shift here. We’ll see!

But like, wtf even is the nervous system? This is an question I ask myself a lot, since I throw the terms “nervous system” and “nervous system regulation” around so often.

So let’s do this.

Here’s the tl;dr:

• The nervous system is a physical entity of nerve tissue in the body, including the central and peripheral nervous system.

• The autonomic nervous system has two branches you’ve probably heard of: sympathetic and parasympathetic. Both are great under the right circumstances, but we generally suck at shifting into and hanging out in the parasympathetic state.

• Our senses of pain, anxiety, and/or calm and ease are all hugely (if not entirely) influenced by the state of the nervous system.

• Nervous system regulation is a far stickier, more subjective concept, that centers on the ability to flexibly respond to different stressors and change states of arousal.

Related reading:

• Here’s why everything always hurts. A dive into chronic pain, neuroplastic pain, and how to work with neuroscience to turn it around.

• What if the pain doesn’t quit? A navigation of the intersection between a condition causing true tissue damage and neuroplastic pain/nervous system dysregulation. SO important if you have an ongoing condition like endometriosis, any rheumatological condition, etc.

• Leaving Las Vagus. A primer on the most famous nerve of the autonomic nervous system, the vagus nerve.

The deep dive:

It’s so important to me to begin with the fact that when I talk about the nervous system, I’m referring to a physical entity — not some woo woo ethereal concept, much as I love me some woo. Nope, according to the National Cancer Institute, the definition of the nervous system is:

The organized network of nerve tissue in the body. It includes the central nervous system (the brain and spinal cord), the peripheral nervous system (nerves that extend from the spinal cord to the rest of the body), and other nerve tissue.

This is the basics of what we’re looking at:

source: Cleveland Clinic

As a clinician, the physical foundation of the nervous system is why I feel passionately about using the body and movement as a tool for its regulation — but more on that later, and maybe another day, too.

Okay, so we’ve got our central nervous system (CNS), which is in pink here, and our peripheral nervous system (PNS) in yellow. But hark! There’s SO MUCH MORE. The PNS breaks down into more parts, many of which you’re probably familiar with:

source: Simple Psychology

Here’s the really important kicker: You can see under the “somatic nervous system” (SNS) that it’s voluntary. We’re generally taught that the autonomic nervous system (ANS) is involuntary, which is generally true, and great, too — like, who loves remembering to breath and beat your heart for every single rep? Not me. We would all be cooked if the ANS were not on autopilot.

BUT! The ANS and the SNS are part of the same branch of the nervous system, and you can influence the ANS by using the SNS. This is why many of us feel more calm after specific movement modalities.

It is also why manual therapy of all stripes works: It is an interaction with your nervous system via input to skin, muscles, and therefore, the peripheral nervous system.

(Small side soap box: All manual therapy works. All manual therapy does not work. Why do some people love “hurts so good” input and some people love hella light touch, like craniosacral therapy? Why are some people hurt by or convinced that the same modalities are a waste of time? It’s because all of us have a differently wired nervous system, and manual therapy is an interaction with it.)

So what does all of this have to do with pain, much less your pelvic floor?

As a reminder, pain is an experience that happens in your brain. I like to say that pain = sensation + fear, and this is a statement backed by neuroscience. I really like this statement from an article entitled General Pathways of Pain Sensation and the Major Neurotransmitters Involved in Pain Regulation:

Pain is considered to be a human primate instinct and can be defined as a distressing sensation, as well as an emotional experience that is linked to actual or potential tissue damage, with the sole purpose of notifying the body’s defense mechanism to react towards a stimulus in order to avoid further tissue damages.

Note the word “distressing” and the really important secondary factor of emotional experience.

Importantly, also note the emphasis on how pain is an evolutionary mechanism to keep us alive. You’re not making any pain that you experience up. Any and all pain is a real experience, driven by an up-regulation of our nervous system to support survival.

When it comes to chronic pain, the question in my mind is always about whether or not there is room to down-regulate the nervous system, increase sensations of safety, and reduce — or even eliminate — the pain experience.

It’s easy to think about the whole concept of “rest and digest” versus “fight or flight” as intangible states, but these are physical entities, too:

source: Simply Psychology

It gets more complicated, obvo. The important thing to know is that there are specific nerve and spinal cord segments which have either solely parasympathetic or sympathetic fibers, or both. This is why one needs to be in a parasympathetic state to take a good shit.

See that small box at the bottom, under reproductive system? When this infographic talks about blood flow, it probably is referencing sexual arousal. But bodies don’t discriminate, and blood flow is critical for reducing muscle tension and maximizing nerve function. Too much sympathetic time, then, creates chronic muscle tension, which we all know leads to bad times in the pelvic floor (pain, incontinence, etc. etc.).

We can also see that the bladder is highly impacted by sympathetic and parasympathetic stimulation. So while I’m certainly not saying that stress incontinence is caused by too much mental stress (patently false), I am saying that it’s exacerbated by it.

This is true of prolapse, too. While stress doesn’t cause prolapse per se, holding one’s breath sure as shit can, and regardless, perception of prolapse symptoms will be heightened in a chronically sympathetic state. This is, in general, true of most non-pain related conditions, as well as conditions that cause true tissue damage (like endometriosis): a sympathetic state can significantly worsen pain and discomfort.

Here’s the take-home:

When I think about “nervous system regulation” it feels really slippery. To me, it’s more of a feeling than a concrete definition, but I really like this one:

Nervous System Regulation is, at its core, the ability to move flexibly between different states of arousal in response to stressors.

When I am personally well-regulated, my voice noticeably drops, and my brain feels grounded and slower (in a good way).

On the inverse, I can spot dysregulation in myself and others from a mile away: lots of talking, a hyper-fixation on what’s gone wrong, a kind of spinning narrative around the million possible ways to attack the problem (or why it’s impossible to approach the problem).

There’s no correct way to regulate one’s nervous system. Bodies are different. Brains are different. Some folks get regulated from running marathons, god bless them (I cannot run a mile), while others get it from a breath work session, or walking in nature, or lifting. I also highly recommend using the sensory system — visuals, audio input, smells, touch, etc. — to modulate how you feel.

While I’m a huge fan of creating a soothing environment, I’m going to take a moment to plug rituals that soothe your nervous system. This can be anything; thirty seconds of breath before opening the car door to go to work or an hour of daily yoga — and anything in between. Having a routine — something your system can expect on the regular — can be soothing in and of itself.

If this idea seems absolutely fucking impossible, I see you. I get it. We’ll talk more next week.

As always, I am rooting for you. Drop me a line or comment here if you feel like it — I would love to hear from you!