Cortisol is the most misunderstood hormone in popular health writing. It is sold as the cause of belly fat, exhaustion, poor sleep and almost everything else, usually alongside a supplement.
What it actually does is regulate your response to demand. It peaks about thirty minutes after waking, falls through the day, and reaches its lowest point around midnight. That daily rhythm matters more than the absolute level.
Chronic stress disturbs the rhythm rather than simply raising the number, which is why symptoms often look like a pattern rather than a single problem.
Fourteen questions covering the symptoms most consistently associated with a disturbed stress response: sleep pattern, energy through the day, cravings, mood, and physical signs.
The result describes symptom burden. It cannot measure cortisol, and no questionnaire can.
The description women and men both use is wired but tired. Exhausted by evening, then alert at bedtime. Waking at three or four in the morning, mind running. Energy that crashes mid-afternoon and returns at nine at night.
That is a rhythm problem, and it responds to different things than simple tiredness does.
This deserves saying plainly, because it is heavily marketed.
Adrenal fatigue is not a recognised medical diagnosis. Systematic reviews have found no consistent evidence that the adrenal glands become exhausted from stress in the way the concept describes.
What does exist is adrenal insufficiency, a serious and uncommon condition diagnosed with specific blood tests, and a disturbed cortisol rhythm, which is real and responds to sleep, light exposure and load management rather than to supplements.
Saliva cortisol panels sold direct to consumers are not validated for diagnosing either.
Consistent wake time, including weekends. The cortisol rhythm is anchored to when you wake, not when you sleep.
Morning daylight within an hour of waking, which reinforces the peak that should happen then.
Training load. Excessive training raises cortisol and produces symptoms identical to stress. If you train hard and feel worse rather than better, that is worth examining.
Alcohol. It disrupts the second half of the night reliably, which is where the three-in-the-morning waking often comes from.
If symptoms persist despite these, thyroid function, ferritin and blood glucose are worth checking before concluding anything about cortisol.
Related reading: The adrenal fatigue myth · Cortisol and stress hormones · Cortisol and the pre-lunch crash · Sleep quality score
Educational only, not medical advice.