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A cortisol level test uses a blood sample to measure the level of cortisol present in your blood.
Cortisol is a steroid hormone released by the adrenal glands. The adrenal glands sit on top of your kidneys. A cortisol level test may also be called a serum cortisol test.
Cortisol is a steroid hormone produced by the adrenal glands. Whenever you experience something your body perceives as a threat, like a large dog barking at you, a chemical known as adrenocorticotropic hormone (ACTH) is released in your brain. This triggers your adrenal glands to release cortisol and adrenaline.
Cortisol is the main hormone involved in stress and the fight-or-flight response. This is a natural and protective response to a perceived threat or danger. Increased levels of cortisol result in a burst of new energy and strength.
In the fight-or-flight response, cortisol suppresses any functions that are unnecessary or detrimental to that response. During a fight-or-flight response, you can have:
Cortisol release also:
The cortisol level test is used to check if your cortisol production levels are either too high or too low. There are certain diseases, such as Addison’s disease and Cushing’s disease, which affect the amount of cortisol your adrenal glands produce. The test is used in the diagnosis of these diseases and as a way to assess the functioning of the adrenal and pituitary glands.
Cortisol plays a role in several systems in the body. These systems include:
A blood sample is used to measure cortisol levels. Most blood samples are collected using this process:
There are few risks associated with the cortisol level test. The test is done by taking a blood sample from your vein, which may result in some bruising at the site where the needle was inserted.
In rare cases, the following risks may be associated with having blood drawn from your vein:
Cortisol levels vary throughout the day, but they’re usually highest in the morning. Your doctor will usually request that the test is done in the morning for this reason. You don’t need to fast for a cortisol test.
There are certain drugs that affect cortisol levels. Your doctor may request that you not take these drugs before the test is done. Cortisol levels are sometimes increased by:
Cortisol levels are sometimes decreased by:
Cortisol levels can also be affected by physical stress, emotional stress, and illness. This is due to the increased release of ACTH by the pituitary gland during the normal stress response.
Normal results for a blood sample taken at 8 a.m. range between 6 and 23 micrograms per deciliter (mcg/dL). Many laboratories have different measuring techniques, and what’s considered normal may vary.
Higher-than-normal cortisol levels may indicate that:
Lower-than-normal cortisol levels may indicate that:
Your doctor will go over your test with you. They may order more tests if they believe that the levels of cortisol in your blood are too high or too low.
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