Plasma Cortisol

Health Care


Health Care

Cortisol is the main hormone secreted by the adrenal glucorticoïde. The serum cortisol can detect an abnormality of the adrenal Cushing syndrome or adrenal insufficiency.


It is to meter the final compound of the biosynthesis of glucocorticoids: cortisol.

plasma cortisol

Blood Sample on heparin tube, fasting and rest, at 8 am (maximum rate of time in case of adrenal insufficiency).

The blood is centrifuged in the hour.

If Cushing’s syndrome is suspected, a sample is taken at 8 am and 20 pm, hours when rates are normally lower.


Normal values:

– 8 pm: 100 to 200 mg / L or 250-550 mmol / L;

– 20 h: less than 100 mg / L or 250 mmol / L;

– In children under 10 years: 50 to 100 g / L;

– Free plasma concentration: 10 to 20 g / L.

Pathological changes:

– A high rate at 8 am and comparable or higher at 20 h is in favor of Cushing’s syndrome, confirmed by a normal ACTH, very high in case of adrenal tumor;

– A low rate to 8 pm that does not increase after a stimulation test Synacthene Delay sign adrenal insufficiency.



Practical advice:

In women, the results can be skewed if pregnant or taking estrogen.

They are also in the event of physical activity prior to the blood test, stress or alcoholism.

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