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Cortisol test
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The cortisol test measures how much cortisol is in the blood, the urine, or the saliva. Cortisol is a hormone, meaning a chemical messenger that travels through the blood, and it is made by the adrenal glands, two small glands that sit on top of the kidneys.
Another hormone gives the order: ACTH, which tells the adrenal gland how much cortisol to make. And because the level is not fixed but rises and falls over the course of the day, a single snapshot does not tell the whole story. That is why blood is usually drawn in the morning and again in the afternoon.
The test is used to support or rule out two kinds of problem. One is too much cortisol, as in Cushing syndrome. The other is too little cortisol, as in Addison disease.
In brief
The cortisol test measures this hormone in blood, urine, or saliva; it is made by the adrenal glands, two small glands that sit atop the kidneys.
ACTH tells the adrenal gland how much to make, and because the level shifts through the day, blood is usually drawn in the morning and again in the afternoon.
The level rises and falls during the day, so a single snapshot is not enough.
It helps support or rule out high cortisol, as in Cushing syndrome, or low cortisol, as in Addison disease.
Sources (1)
- MedlinePlus, U.S. National Library of MedicineCortisol Test, MedlinePlus Medical TestPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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