What Is HPA Axis Dysfunction?

The HPA (Hypothalamic-Pituitary-Adrenal) axis is your body's stress command center—a hormonal group chat between your brain and adrenal glands that manages how you respond to stress, regulate energy, sleep, immunity, digestion, and even mood. When it’s functioning properly, it’s Beyoncé-level flawless.

But when the stress won’t quit—deadlines, toddlers, perimenopause, your neighbor’s leaf blower at 7 a.m.—this communication line gets frazzled. The result? Dysregulation. Also known as: HPA Axis Dysfunction.

Is That the Same as Adrenal Fatigue?

Short answer: No, but we get why people say that.

"Adrenal fatigue" is the common (and controversial) term for this issue, and it implies your adrenal glands are simply too pooped to function. But in reality, the adrenals aren't broken—they’re responding to a dysregulated signal from the brain. That’s like blaming your microwave when the power’s out.

So while you may feel tired, wired, puffy, moody, or totally burnt out, the deeper problem is your HPA axis being on the fritz.

Why Is This Happening?

Let’s play chronic stress bingo:

✅ Overworking
✅ Undereating
✅ Skipping sleep
✅ Emotional stress
✅ Too much HIIT
✅ Caffeine-fueled coping
✅ Perimenopause chaos

These all add up. Your brain gets a constant “we’re in danger!” signal, and it keeps pumping out cortisol until the system either short-circuits (too much) or crashes (too little).

Cortisol 101

Cortisol is your body’s main stress hormone. It’s not evil—it helps you wake up, focus, and deal with life. But it becomes problematic when it’s either overproduced or chronically low.

Normal cortisol follows a rhythm: it peaks 30–45 minutes after waking (called the cortisol awakening response) and slowly declines throughout the day. When this curve shifts, symptoms start showing up—and we can see it clearly in salivary cortisol testing.

What Can Saliva Testing Tell Us?

Saliva testing is like reality TV for your hormones—it shows what they’re doing all day long, not just a snapshot. A 4-point salivary cortisol test (taken morning, noon, afternoon, and night) tells us:

• If cortisol is high at night (hello, insomnia)
• If it’s low in the morning (struggling to get out of bed?)
• If it’s flatlined all day (classic burnout)

Bonus: saliva also measures DHEA, the body’s "feel good" hormone and a precursor to sex hormones. Low DHEA plus low cortisol? You're in the burnout basement.

The Phases of HPA Axis Dysfunction (a.k.a. "Adrenal Fatigue")

When stress is ongoing, your body’s cortisol curve begins to shift. These shifts happen in stages:

Phase 1: "Wired But Tired"

Also called early HPA axis dysregulation. Cortisol levels are erratic—either too high or zigzagging through the day. People in this phase feel wired, edgy, but also tired. Sleep may be disrupted, and stress response is heightened.

Phase 2: "Sluggish and Scattered"

Also known as evolving dysregulation. Cortisol levels begin to drop, the curve flattens slightly, and energy is harder to come by. You may feel foggy, struggle with motivation, or get bursts of energy at all the wrong times (like bedtime).

Phase 3: "Flatlined Burnout"

This is established HPA dysfunction. The cortisol curve has lost its shape, often resembling a flat line. People in phase 3 experience profound fatigue, poor sleep, reduced resilience, and may begin rationing energy for essentials (like skipping workouts just to survive work).

Does This Mess With My Sex Hormones Too?

Oh, absolutely.

When your body is in stress-survival mode, it diverts resources away from hormones like estrogen, progesterone, and testosterone.

• Progesterone gets "stolen" to make more cortisol (this is called the pregnenolone steal)
• Estrogen gets erratic, leading to mood swings, weight gain, and night sweats
• Libido leaves the chat

This is even more disruptive in perimenopause when your hormones are already roller-coastering.

Why This Matters

Regardless of the phase you’re in, HPA axis dysfunction can absolutely change how you feel, function, and move through life. Understanding your stress response pattern helps explain the “why” behind your fatigue, mood, sleep, or hormonal symptoms.

Best of all, it gives you a roadmap to get back on track—through strategic supplementation, lifestyle changes, and yes, reclaiming your bandwidth.

References

• Hellhammer, D. H., Wühst, S., & Kudielka, B. M. (2009). Salivary cortisol as a biomarker in stress research. Psychoneuroendocrinology, 34(2), 163–171. https://doi.org/10.1016/j.psyneuen.2008.10.026
• Lovallo, W. R., et al. (2010). Stress habituation, BMI and daily cortisol activity in young men. Hormones and Behavior, 58(5), 842–849. https://doi.org/10.1016/j.yhbeh.2010.07.012
• Roberts, A. D. L., et al. (2004). Salivary cortisol response to awakening in chronic fatigue syndrome. British Journal of Psychiatry, 184(2), 136–141. https://doi.org/10.1192/bjp.184.2.136
• Tsigos, C., & Chrousos, G. P. (2002). HPA axis, neuroendocrine factors and stress. Journal of Psychosomatic Research, 53(4), 865–871. https://doi.org/10.1016/S0022-3999(02)00429-4