Cortisol in Blood

Free Cortisol Test, Hydrocortisone Test

Results

A cortisol test is done to measure the level of the hormone cortisol in the blood.

Normal

Normal results may vary from lab to lab.

Cortisol

Adult	Morning	138–635 nanomoles per litre (nmol/L) or 5–23 micrograms per decilitre (µg/dL)
	Afternoon	83–359 nmol/L or 3–13 µg/dL
Child	Morning	83–580 nmol/L or 3–21 µg/dL
	Afternoon	83–276 nmol/L or 3–10 µg/dL
Newborn		27–663 nmol/L or 1–24 µg/dL

High values

• A high level of cortisol in the blood can mean Cushing's syndrome, a disorder that can be caused by overactive adrenal glands, a pituitary or adrenal gland tumour, some types of cancer, or long-term use of corticosteroids.
• One cause of Cushing's syndrome is Cushing's disease, a condition caused by a non-cancerous tumour of the pituitary gland (adenoma). An adenoma causes the pituitary gland to make too much of the hormone adrenocorticotropic hormone (ACTH), which in turn causes the adrenal glands to make too much cortisol.
• A high blood cortisol level can be caused by severe liver or kidney disease, depression, hyperthyroidism, or obesity.
• Conditions such as recent surgery, illness, injury, or whole-body infection (sepsis) can cause high cortisol levels.

Low values

• A low level of cortisol in the blood can mean Addison's disease, which is caused by damage to the adrenal glands. If the pituitary gland is not working well, it can cause low levels of the hormone ACTH, which in turn causes low levels of cortisol. Symptoms of pituitary gland failure are like those of Addison's disease. Conditions that can damage the adrenal glands or pituitary gland include some infections, head injury, and some autoimmune diseases.
• A low level of cortisol can be caused by internal bleeding that leads to shock. For example, severe bleeding during childbirth that causes damage to the pituitary gland of the mother (Sheehan's syndrome) can cause a low level of blood cortisol.

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Author:	Jan Nissl, RN, BS Sydney Youngerman-Cole, RN, BSN, RNC	Last Updated: November 30, 2006
Medical Review:	Caroline S. Rhoads, MD - Internal Medicine Hanan Bassyouni, MD - Endocrinology and Metabolism Alan C. Dalkin, MD - Endocrinology
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