Under Stress: Cortisol

The Story

Stina has spent years feeling “tired but wired,” and her cortisol curve finally put a shape to it. A healthy stress hormone surges in the morning to get the body moving and tapers by night; hers came back flat, the morning peak barely there. To a clinician scanning for disease it looked unremarkable. Read against her history of relentless inflammation, it looked like a stress axisSecond cervical vertebra; has the odontoid process (dens) for pivoting head (“no” motion). that had been switched on for too long.

The adrenal stress response runs along the HPA axis: a stressor drives the hypothalamusA small but vital brain region controlling hormones, temperature, and autonomic functions. to release CRH, which drives the pituitary to release ACTH, which drives the adrenal cortexOuter portion of the adrenal glands producing corticosteroids. to release cortisol — and cortisol feeds back to shut the loop off. Normally cortisol follows a daily rhythm, peaking in the early morning and falling overnight, which is why timing the test matters as much as the number. In Stina, years of relentless IL-1β and IL-6 act as a chronic stressor that keeps the HPA axis activated until the rhythm wears flat — a system first overdriven, then blunted. Her flattened curve isn’t laziness or simple aging; it is the signature of a stress axis that has been answering an inflammatory alarm that never turns off.

From Stina’s chart: Stina’s morning cortisol — the hormone meant to peak as she wakes — comes back blunted and flat. Years of IL-1β and IL-6 have run her stress axis hot, then left it exhausted.