What does the Cortisol test measure?

Why is Cortisol measured?

In the HPA-G profile, cortisol is interpreted as the central marker of hypothalamic-pituitary-adrenal axis activity and stress adaptation. Random urinary cortisol provides a snapshot rather than the integrated assessment of a 24-hour collection or the dynamic information from a salivary diurnal curve. Elevated cortisol suggests chronic stress or HPA activation, while low values raise the possibility of adrenal insufficiency or HPA axis suppression, though single random samples lack the diagnostic power of formal endocrine testing.

Reference ranges

Standard reference

Laboratory-specific functional ranges provided by Sanesco; timing of collection affects interpretation, as cortisol follows a diurnal rhythm.

Functional medicine optimal

Morning values in the upper-mid reference with a clear evening decline. Functional practitioners look for preserved rhythm; flat or inverted curves prompt further investigation.

Units

ng/mg creatinine, μg/g creatinine

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.