Midlife woman looking stressed next to title ‘How Stress Hijacks Your Hormones’ on peach background – blog header about cortisol, hormone imbalance and stress in women over 40.

How Stress Hijacks Your Hormones

November 20, 20253 min read

How Stress Hijacks Your Hormones

Understand the cortisol connection and why chronic stress leads to fatigue, stubborn weight, mood swings, and disrupted sleep.

If you’re a woman in your 40s or 50s, you already know stress feels different now. What used to be manageable suddenly wipes you out, affects your sleep, your mood, your energy — even your waistline.

And there’s a very real reason for that.

Stress isn’t just a feeling — it quietly changes how your body works. It affects everything from your hormones to your sleep, your digestion and your day-to-day sense of balance.

And it all starts with the way your body responds to pressure.


The Stress Response: Your HPA Axis Explained

When your body senses pressure, it triggers the HPA axis — the Hypothalamic–Pituitary–Adrenal axis. This is your internal alarm system that releases cortisol, your main stress hormone.

Here’s what actually happens:

  • The hypothalamus detects stress and releases CRH.

  • The pituitary gland responds with ACTH.

  • The adrenal glands (sitting on top of your kidneys) release cortisol.

This response is helpful in short bursts — it keeps you alert, focused and ready to react.

But when stress becomes chronic, the HPA axis stays switched on for too long.
And that’s when trouble begins.


What Chronic Stress Does to Your Body

When cortisol remains elevated, it starts to disrupt almost every major system.
Common symptoms include:

  • constantly high (or eventually low/irregular) cortisol

  • fatigue, anxiety and irritability

  • sleep disruption, especially 2–4am wake-ups

  • blood sugar swings

  • stubborn midlife weight, particularly around the middle

  • hormone imbalance (oestrogen, progesterone, thyroid, melatonin)

Everything feels “off”… even when you’re eating well, exercising and doing all the right things.


Where the Vagus Nerve Fits In

Once the stress has passed, your body should switch the HPA axis off — and this is where the vagus nerve steps in.

Think of it as the brake on your stress response.

When the vagus nerve is activated, it sends calming “you’re safe now” signals from the body back to the brain. This helps your system downshift:

  • cortisol production decreases

  • heart rate slows

  • digestion restarts

  • inflammation reduces

  • your body shifts out of fight-or-flight mode

But if vagal tone is low — which is increasingly common in midlife — your body can stay “stuck” in stress mode. Cortisol stays high, and that ongoing stress continues to hijack insulin, oestrogen, progesterone and melatonin.


In Simple Terms

  • Chronic stress turns cortisol up.

  • The vagus nerve turns it back down.

  • Until cortisol drops, your hormones can’t find balance.

Or as I often explain it:

“The vagus nerve is one of the body’s main pathways for switching off the stress response. When it’s activated, it sends ‘all clear’ signals back to the brain so cortisol naturally drops. When you’re under pressure, the HPA axis fires up and cortisol rises — but if this keeps happening, cortisol stays elevated for too long. This chronic stress response disrupts insulin, oestrogen, progesterone and melatonin, which is why you see fatigue, stubborn belly weight, mood swings and poor sleep. In short, when cortisol stays high, your hormones are hijacked.”


The Good News

You’re not powerless — far from it.

You can train your body to switch off the stress response.

When you learn to activate and strengthen your vagus nerve, you help your body do something incredibly powerful:

switch out of stress mode more quickly and restore hormonal balance more easily.

And the best part?
It takes less than 10 minutes a day.


✨ Ready to reset your stress response?

Download my 10-Minute Stress Response Toolkit — a simple set of everyday nervous-system resets designed to lower cortisol, calm your body, and support hormone balance.

👉 [Download the 10-Minute Stress Response Toolkit]

Lucy Round is a Certified health and nutrition coach, and creator of the FRESH Framework.

Helping women 40+ naturally rebalance their hormones, restore energy, and finally feel like themselves again 

Through personalised nutrition and evidence-based coaching, she empowers women to regain energy, reduce overwhelm, and feel confident in their long-term health.

Lucy Round

Lucy Round is a Certified health and nutrition coach, and creator of the FRESH Framework. Helping women 40+ naturally rebalance their hormones, restore energy, and finally feel like themselves again Through personalised nutrition and evidence-based coaching, she empowers women to regain energy, reduce overwhelm, and feel confident in their long-term health.

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