The HPA Axis Explained: Why Chronic Stress Isn't in Your Head

The HPA Axis Explained: Why Chronic Stress Isn't in Your Head

By Leslie Burgie, APRN  |  Nurse Practitioner · Women's Hormone Health · 9D Breathwork Facilitator

If you've been told your stress is "just anxiety" or that you need to "think more positively," this post is for you. Chronic stress has a biological mechanism — and it's not in your head.

What Is the HPA Axis?

The HPA axis — hypothalamic-pituitary-adrenal axis — is the central command system of your stress response. It's a communication loop between three key structures in your body, and when it's running well, it keeps you resilient, energized, and able to handle challenges without falling apart. When it's dysregulated, it's the source of some of the most frustrating and misunderstood symptoms in modern medicine.

Here's how it works: when your brain perceives a threat — real or imagined, physical or emotional — the hypothalamus (a small region at the base of your brain) sends a chemical signal to the pituitary gland, which sits just below it. The pituitary then signals the adrenal glands — two small glands sitting on top of your kidneys — to release cortisol. This entire cascade happens within seconds.

Cortisol is often mischaracterized as purely "bad." It isn't. Cortisol is a critical hormone. It mobilizes energy, reduces inflammation in the short term, sharpens focus, and helps you survive genuine threats. The problem isn't cortisol itself — it's cortisol that never turns off.

When the Alarm Gets Stuck

In a healthy stress response, the HPA axis is self-regulating. Cortisol rises in response to a stressor, the stressor resolves, cortisol signals the hypothalamus to stand down, and levels return to baseline. The system resets.

But chronic stress — the kind that comes from financial pressure, relationship strain, professional overwhelm, past trauma, or persistent physical illness — doesn't give the system a chance to reset. The hypothalamus keeps receiving threat signals. Cortisol keeps being released. And over time, the feedback mechanism that should tell the system to stand down becomes less sensitive.

This is called HPA axis dysregulation, and it produces a recognizable pattern of symptoms that I see regularly in clinical practice:

• Fatigue that sleep doesn't fix

• Waking between 2 and 4 AM with a racing mind

• Anxiety that doesn't have a clear source

• Brain fog and difficulty concentrating

• Cravings for sugar, salt, or caffeine

• Mood instability — fine one hour, tearful or irritable the next

• Reduced tolerance for stress over time

These symptoms are often dismissed or attributed to anxiety disorders, depression, or lifestyle factors. Sometimes those labels are accurate. But frequently, what's being described is a hormonal system that has been running in overdrive for so long it has lost its ability to self-regulate.

The Cortisol-Sleep-Anxiety Loop

One of the most clinically significant consequences of HPA dysregulation is its interaction with sleep. Cortisol follows a diurnal rhythm — it should be highest in the morning (giving you energy to start the day) and lowest at night (allowing your body to shift into repair and recovery mode).

When the HPA axis is dysregulated, this rhythm gets flattened or inverted. Cortisol may be low in the morning (making it hard to get out of bed) and elevated at night (making it hard to fall or stay asleep). Poor sleep then triggers the release of more cortisol the next day — and the loop reinforces itself.

Chronically elevated cortisol also suppresses progesterone production, disrupts thyroid function, impairs immune regulation, and over time, contributes to insulin resistance. This is why chronic stress is not just a mental health issue — it is a whole-body hormonal issue.

Why "Just Relax" Doesn't Work

If you've ever been told to reduce your stress and felt frustrated because you didn't know how to actually do that, you're not missing something obvious. You're up against a physiological loop that doesn't respond to willpower or positive thinking.

Cognitive approaches — therapy, journaling, mindset work — are genuinely valuable. But they work at the level of conscious thought. The HPA axis operates below that level. It responds to physiological signals: movement, sleep, nutrition, social connection, and direct nervous system interventions like breathwork.

This is why I work at both ends of this equation. Through Optimize & Elevate, I address the hormonal scaffolding — supporting the HPA axis through clinical assessment, targeted supplementation, and when appropriate, hormone therapy. Through The Breath Detox, I work with the nervous system directly, using 9D Breathwork to create a physiological experience of safety that signals the HPA axis to finally, genuinely, stand down.

Both approaches matter. Hormones and nervous system regulation are not separate conversations — they're the same conversation.

What You Can Do

If you recognize yourself in this post, the most important thing I want you to know is this: what you're experiencing has a biological basis, it is not a character flaw, and it is addressable.

Start with what you can influence directly:

• Protect your sleep — cortisol rhythm restoration begins with consistent sleep and wake times

• Move your body daily — even a 20-minute walk activates parasympathetic recovery

• Reduce inflammatory inputs — ultra-processed foods, alcohol, and chronic undereating all stress the HPA axis

• Add a nervous system practice — breathwork, yoga nidra, or meditation practiced consistently will shift HPA tone over time

• Get a clinical picture — if you suspect HPA dysregulation, a 4-point salivary cortisol test gives a clearer view than a single blood draw

If you're in Ohio and want clinical support for HPA axis dysregulation, hormone testing, or a comprehensive look at what's driving your symptoms, I work with patients virtually through Optimize & Elevate at optimizeandelevate.com.

And if you want to experience what it feels like to give your nervous system a direct reset, I offer live 9D Breathwork sessions through The Breath Detox at thebreathdetox.com. The body often knows what it needs — sometimes it just needs the right conditions to let go.

About the Author

Leslie Burgie, APRN is a nurse practitioner, women's hormone health specialist, and certified 9D Breathwork facilitator based in Ohio. She operates two virtual practices: Optimize & Elevate (optimizeandelevate.com), a women's hormone health practice serving Ohio, and The Breath Detox (thebreathdetox.com), a 9D Breathwork facilitation practice. Her clinical work focuses on the intersection of HPA axis regulation, hormonal health, and somatic nervous system healing.