Cortisol in Blood

Free Cortisol Test, Hydrocortisone Test

Test Overview

A cortisol test is done to measure the level of the hormone cortisol in the blood. The cortisol level may show problems with the adrenal glands or pituitary gland. Cortisol is made by the adrenal glands Click here to see an illustration.. Cortisol levels go up when the pituitary gland Click here to see an illustration. releases another hormone called adrenocorticotropic hormone (ACTH).

Cortisol has many functions. It helps the body break down food for energy (metabolism), and it helps the body manage stress. Cortisol levels can be affected by many conditions, such as physical or emotional stress, strenuous activity, infection, or injury.

Normally, cortisol levels rise during the early morning hours and are highest about 7 a.m. They drop very low in the evening and during the early phase of sleep. However, if you sleep during the day and are up at night, this pattern may be reversed. If you do not have this daily change (diurnal rhythm) in cortisol levels, you may have overactive adrenal glands. This condition is called Cushing's syndrome.

Two blood samples may be taken: one in the morning and another in the afternoon.


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Author: Jan Nissl, RN, BSLast Updated August 21, 2006
Medical Review: Caroline S. Rhoads, MD - Internal Medicine
Alan C. Dalkin, MD - Endocrinology

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Topic Contents
Arrow PointerTest Overview
 Why It Is Done
 How To Prepare
 How It Is Done
 How It Feels
 Risks
 Results
 What Affects the Test
 What To Think About
 References
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