The Foundation That Runs Everything Else - Nervous System

Why your nervous system is the root of every symptom you're experiencing — and what to actually do about it.

A few weeks ago we talked about your pelvic floor. After that, I went deep on bloating, weight gain, and sugar cravings. If you’ve been reading along, you might have noticed a thread running through all of it — a sense that these things aren’t random, that they’re connected.

They are. And the connection is your nervous system.

This is Foundation 1 in my 5 Foundations framework. Not because I arbitrarily put it first, but because nothing else works until this one is addressed. Your nutrition, your movement, your skin, your environment — all of it is filtered through a nervous system that is either regulated or dysregulated. When it’s dysregulated, even the most “perfect” protocol won’t give you the results you’re looking for.

So today I start here. With the foundation that runs everything else.

What’s actually happening — and why it’s not in your head

Let’s start with the biology, because I want you to understand this — really understand it.

Your body runs on a stress-response system called the HPA axis (hypothalamic-pituitary-adrenal axis). Think of it as your body’s internal alarm system. When it senses a threat — real or perceived — it floods your body with cortisol and adrenaline to help you respond.

Here’s where perimenopause changes everything.

Estrogen plays a crucial regulatory role in keeping the HPA axis calibrated. It acts as a natural buffer, helping cortisol responses stay proportionate and recover quickly. When estrogen starts to fluctuate and decline — which is what perimenopause is — that buffer weakens. Your stress response becomes more reactive, takes longer to come back down, and costs your body far more than it used to.

The result? Your nervous system is essentially working in a heightened state more of the time. Small things feel bigger. Recovery takes longer. Sleep becomes harder. And the symptoms cascade: disrupted sleep raises cortisol further, elevated cortisol drives blood sugar instability, blood sugar instability creates cravings and weight gain — which in turn feeds more stress on an already taxed system.

📚 The Research

HPA axis and estrogen: Research published in the Archives of Women’s Mental Health confirms that declining estradiol levels significantly impact HPA axis regulation, increasing vulnerability to stress-related symptoms during perimenopause.

Nervous system reactivity: A 2024 study in Frontiers in Psychiatry found that perimenopausal women show measurably higher autonomic nervous system reactivity compared to premenopausal controls — meaning the nervous system itself becomes more sensitised during this transition.

The cortisol-sleep loop: The Journal of Physiology (2024) documents the bidirectional relationship between sleep disruption and cortisol dysregulation in midlife women, where each worsens the other in a reinforcing cycle.

The confidence piece — because this matters and nobody talks about it directly

I want to talk about something that doesn’t get enough airtime in conversations about perimenopause: confidence.

Not the kind of confidence that’s about self-belief or “mindset.” I mean the embodied sense of trust in yourself — the feeling of being grounded in who you are, what you know, and what you’re capable of. For many women in perimenopause, that sense quietly erodes. And it happens so gradually that most women assume it’s something they’ve done wrong.

It’s not. And the science explains why.

A 2023 study published in the National Library of Medicine found that perimenopausal and menopausal women report significantly lower self-esteem and self-confidence compared to their pre-perimenopausal selves — and that these changes correlate directly with symptom severity, not simply with age. When your body is symptomatic and your sleep is disrupted and your stress system is running hot, your confidence suffers. These aren’t separate issues.

Research published in ScienceDirect confirms a direct correlation between menopause symptom burden and self-esteem — meaning the more symptomatic you are, the more your sense of yourself is impacted. And a study in Women & Health documented that body image changes during perimenopause significantly affect psychological wellbeing, particularly in women who had previously had a stable relationship with their bodies.

The British Menopause Society has also reported that up to 20% of women consider leaving the workforce during perimenopause — and one of the primary drivers is a loss of confidence in their professional abilities. Not because they’ve become less capable. Because their nervous system is under extraordinary strain and their brain is working harder to do what used to come naturally.

“Confidence in perimenopause isn’t rebuilt through willpower. It’s rebuilt by stabilising the system that confidence runs on.”

I say this because I’ve felt it myself. The goal is not to push through or fake it. The goal is to create the physiological conditions where confidence can return — and it does return, when the system is supported.

5 things you can do to support your nervous system — and start rebuilding from the inside out

These aren’t quick fixes. They’re practices — small, consistent things that compound over time and create real change in how your nervous system functions. Start with one. Do it daily for two weeks. Then add another.

1

Regulate before you react — morning matters most

Your cortisol is naturally at its highest in the first 30–60 minutes after waking. This is normal. But in perimenopause, that morning cortisol spike can be exaggerated — and how you respond to it sets the tone for your entire nervous system for the rest of the day.

Before you check your phone, before you respond to anyone, take 5 minutes for yourself. A few slow breaths (longer exhale than inhale). A moment outside if you can. Something warm to drink. You’re not just relaxing — you’re signalling to your nervous system that today is safe.

2

Protein stabilises more than your blood sugar

Blood glucose instability is one of the most underrated drivers of nervous system dysregulation in perimenopause. When blood sugar drops, your body triggers a cortisol response to raise it — which means poor eating patterns can keep your stress response activated all day long.

Aim for 25–35g of protein within an hour of waking. This isn’t about macros or dieting — it’s about giving your nervous system a stable chemical environment to work from. Foundation 2 (Nutrition) goes much deeper into this, but this one shift alone can noticeably change your mood stability and energy within two weeks.

3

Name what you’re feeling — specifically

Research from UCLA (Lieberman et al.) showed that simply labelling an emotion — not just “I’m stressed” but “I’m overwhelmed because I have too many decisions to make today” — significantly reduces amygdala activation. In plain English: naming what you feel calms your brain down at a neurological level.

This is not journalling as a chore. It’s a 60-second check-in. Once a day, ask yourself: what am I actually feeling right now? Be specific. The more precise the label, the greater the nervous system effect.

4

Move in ways that complete the stress cycle

Your nervous system is designed to mobilise energy (to run, fight, respond) and then discharge it. In modern life, we activate the stress response constantly but rarely complete the cycle — we stay in the activation without the release.

Physical movement is one of the most effective ways to complete that cycle, especially rhythmic, repetitive movement: walking, swimming, cycling, dancing. Not punishing exercise — movement that flows. Foundation 3 (Movement) will go into much more detail on this, but for now: aim for 20 minutes of rhythmic movement daily, especially on high-stress days.

5

Borrow confidence from your body, not your mind

When confidence is low, we tend to try to think our way back to it. But research on posture and physiology (including work building on Amy Cuddy’s foundational studies) shows that body position actually influences hormonal output — open, upright postures are associated with lower cortisol and more stable stress responses.

This isn’t about “faking it.” It’s about using your body as an input to your brain, rather than waiting for your brain to feel better before you move differently. Stand tall. Take up space. Breathe. These aren’t performance — they’re physiology.

Coming up next: Foundation 3 — Movement

Once your nervous system has a foundation of support, movement becomes something completely different — not a punishment, not a performance metric, but a genuinely restorative tool. Next time, we’ll talk about what that actually looks like during perimenopause and why everything you’ve been told about exercise might be working against you.

If this article resonated with you, share it with a woman you know who’s in the middle of this transition. The more women understand what’s actually happening in their bodies, the less time we spend blaming ourselves.

Leila