Biomarker Reference · Cortisol
Cortisol (urine, diurnal) (Cortisol) is a clinical biomarker used in neurological-mental-health assessment. Cortisol is the principal glucocorticoid in humans, synthesised in the adrenal zona fasciculata under ACTH control with a diurnal rhythm peaking shortly after waking and declining through the day. It is measured in 1 laboratory test on BiomarkersLabs.com.
Cortisol is the principal glucocorticoid in humans, synthesised in the adrenal zona fasciculata under ACTH control with a diurnal rhythm peaking shortly after waking and declining through the day. Free cortisol is filtered by the kidneys; urine cortisol reflects integrated secretion over the collection interval and is less affected by acute sampling stress than single serum samples.
Diurnal urine cortisol sampling captures the rhythm and total cortisol output. Loss of the normal decline (flattened rhythm) is seen in chronic stress, Cushing syndrome, and some psychiatric disorders. Low output across the day may suggest adrenal insufficiency or HPA-axis dysregulation. Dried-urine multiple-timepoint collections are used in functional-medicine assessment of HPA-axis rhythm, though diagnostic endocrinology relies on 24-hour urine free cortisol, saliva, or serum for Cushing or Addison screening.
Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.
1 test on BiomarkersLabs.com include this biomarker.
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