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
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:
- rapid heart rate
- dry mouth
- stomach upset
Cortisol release also:
- suppresses your growth processes
- suppresses your digestive system
- suppresses your reproductive system
- changes how your immune system responds
Is the Cortisol Level Test Performed?
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 gland produces. The test is used in the diagnosis of
these diseases and as a way to assess the functioning of the adrenal and
Cortisol plays a role in several systems in the body. These
- stress responses
- immune system
- nervous system
- circulatory system
- skeletal system
- the breakdown of proteins, fats, and
Is the Cortisol Level Test Done?
A blood sample is used to measure cortisol levels. Most
blood samples are collected using this process:
- The flow of blood in the arm is stopped by
wrapping an elastic band around your upper arm. This also causes the veins in
your arm to become more visible, which makes it easier to insert the needle.
- Alcohol is used to clean the site on your skin
where the needle will be inserted.
- The needle is inserted into the vein. This may
cause a brief pinching or stinging sensation.
- Your blood is collected in a tube that’s
attached to the needle. More than one tube may be needed.
- The elastic band is removed after enough blood
has been collected.
- As the needle is removed from your skin, cotton
or gauze is placed on the site of the needle insertion.
- Pressure is applied to the area using cotton or
gauze. A bandage is used to secure the cotton or gauze.
There Risks Associated with the Cortisol Level Test?
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:
- excessive bleeding
- an accumulation of blood beneath your skin,
which is called a hematoma
- lightheadedness or fainting
to Prepare for the Cortisol Level Test
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.
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:
- drugs containing estrogen
- synthetic glucocorticoids, such as prednisone
Cortisol levels are sometimes decreased by:
- drugs containing androgens
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.
Do the Results of the Cortisol Level Test Mean?
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.
levels may indicate that:
- your pituitary gland is releasing too much ACTH
due to a tumor or excess growth of the pituitary gland
- you have a tumor in your adrenal gland,
resulting in excess cortisol production
- you have tumor elsewhere in your body that’s
involved in cortisol production
levels may indicate that:
- you have Addison’s disease, which occurs when
production of cortisol by your adrenal glands is too low
- you have hypopituitarism, which occurs when
production of cortisol by your adrenal glands is too low because the pituitary
gland is not sending proper signals
Your doctor will go over your test results with you. They
may order more tests if they believe that the levels of cortisol in your blood
are too high or too low.