The Cortisol, Total test contains 1 test with 1 biomarker.
Description: A cortisol test measures the amount of cortisol in the blood. These levels will start off high in the morning and throughout the say they become lower. At midnight they are typically at their lowest level. Someone who works a night shift or has an irregular sleep schedule may have a different pattern. This test can be used to determine Cushing's or Addison's Disease.
Also Known As: Cortisol Total Test, Cortisol Test, Cortisol Blood Test
Collection Method: Blood Draw
Specimen Type: Serum
Test Preparation: Test not recommended when patient is on prednisone/prednisolone therapy due to cross reactivity with the antibody used in this test
When is a Cortisol Total test ordered?
When a person has symptoms that point to a high level of cortisol and Cushing syndrome, a cortisol test may be recommended.
Women with irregular menstrual periods and increased facial hair may be tested, and children with delayed development and small stature may also be tested.
When someone exhibits symptoms that point to a low cortisol level, adrenal insufficiency, or Addison disease, this test may be ordered.
What does a Cortisol Total blood test check for?
Cortisol is a hormone that plays a function in protein, lipid, and carbohydrate metabolism. It has an effect on blood glucose levels, blood pressure, and immune system regulation. Only a small fraction of cortisol in the blood is "free" and biologically active; the majority is attached to a protein. Cortisol is a hormone that is produced into the urine and found in the saliva. This test determines how much cortisol is present in the blood, urine, or saliva.
Cortisol levels in the blood usually rise and fall in a pattern known as "diurnal variation." It reaches its highest point early in the morning, then gradually decreases over the day, reaching its lowest point around midnight. When a person works irregular shifts and sleeps at different times of the day, this rhythm might fluctuate, and it can be disrupted when a disease or condition inhibits or stimulates cortisol production.
The adrenal glands, two triangle organs that sit on top of the kidneys, generate and emit cortisol. The hypothalamus in the brain and the pituitary gland, a small organ below the brain, control the hormone's production. The hypothalamus produces corticotropin-releasing hormone when blood cortisol levels drop, which tells the pituitary gland to create ACTH. The adrenal glands are stimulated by ACTH to generate and release cortisol. The brain, pituitary, and adrenal glands must all be operating properly in order to produce enough levels of cortisol.
Cushing syndrome is a collection of signs and symptoms associated with an unusually high cortisol level. Cortisol production may be increased as a result of:
- Large doses of glucocorticosteroid hormones are given to treat a range of ailments, including autoimmune illness and certain cancers.
- Tumors that produce ACTH in the pituitary gland and/or other regions of the body.
- Cortisol production by the adrenal glands is increased as a result of a tumor or abnormal expansion of adrenal tissues.
Rarely, CRH-producing malignancies in various regions of the body.
Cortisol production may be reduced as a result of:
- Secondary adrenal insufficiency is caused by an underactive pituitary gland or a pituitary gland tumor that prevents ACTH production.
- Primary adrenal insufficiency, often known as Addison disease, is characterized by underactive or injured adrenal glands that limit cortisol production.
After quitting glucocorticosteroid hormone medication, especially if it was abruptly stopped after a long time of use.
Lab tests often ordered with a Cortisol Total test:
- Cortisol PM
- Cortisol AM
- Cortisol Saliva
- Growth Hormone
Conditions where a Cortisol Test is recommended:
- Addison’s Disease
- Cushing’s Syndrome
- Endocrine Syndromes
- Pituitary Disorders
How does my health care provider use a Cortisol Total test?
A cortisol test can be used to detect Cushing syndrome, which is characterized by an excess of cortisol, as well as adrenal insufficiency or Addison disease, which are characterized by a deficiency of cortisol. Cortisol is a hormone that regulates protein, lipid, and carbohydrate metabolism, among other functions. Cortisol levels in the blood normally increase and fall in a "diurnal variation" pattern, rising early in the morning, dropping during the day, and reaching their lowest point around midnight.
The adrenal glands generate and excrete cortisol. The hypothalamus in the brain and the pituitary gland, a small organ below the brain, control the hormone's production. The hypothalamus produces corticotropin-releasing hormone when blood cortisol levels drop, which tells the pituitary gland to create ACTH. The adrenal glands are stimulated by ACTH to generate and release cortisol. The brain, pituitary, and adrenal glands must all be operating properly in order to produce enough levels of cortisol.
Only a small fraction of cortisol in the blood is "free" and biologically active; the majority is attached to a protein. Blood cortisol testing assesses both protein-bound and free cortisol, but urine and saliva cortisol testing assesses only free cortisol, which should be in line with blood cortisol levels. Multiple blood and/or saliva cortisol levels collected at various times, such as 8 a.m. and 4 p.m., can be used to assess cortisol levels and diurnal variation. A 24-hour urine cortisol sample will not reveal diurnal variations; instead, it will assess the total quantity of unbound cortisol voided over the course of 24 hours.
If an elevated amount of cortisol is found, a health professional will conduct additional tests to confirm the results and discover the cause.
If a person's blood cortisol level is abnormally high, a doctor may order additional tests to be sure the high cortisol is indeed abnormal. Additional testing could involve monitoring 24-hour urinary cortisol, doing an overnight dexamethasone suppression test, and/or obtaining a salivary sample before sleep to detect cortisol at its lowest level. Urinary cortisol testing necessitates collecting urine over a set length of time, usually 24 hours. Because ACTH is released in pulses by the pituitary gland, this test can assist evaluate whether a raised blood cortisol level is a true rise.
An ACTH stimulation test may be ordered if a health practitioner feels that the adrenal glands are not releasing enough cortisol or if initial blood tests reveal insufficient cortisol production.
ACTH stimulation is a test that measures the amount of cortisol in a person's blood before and after a synthetic ACTH injection. Cortisol levels will rise in response to ACTH stimulation if the adrenal glands are functioning normally. Cortisol levels will be low if they are damaged or not working properly. To distinguish between adrenal and pituitary insufficiency, a lengthier variant of this test can be used.
What do my Cortisol Total test results mean?
Cortisol levels are typically lowest before bedtime and highest shortly after awakening, though this pattern can be disrupted if a person works rotating shifts and sleeps at various times on separate days.
Excess cortisol and Cushing syndrome are indicated by an increased or normal cortisol level shortly after awakening, as well as a level that does not diminish by bedtime. If the excess cortisol is not suppressed after an overnight dexamethasone suppression test, the 24-hour urine cortisol is elevated, or the late-night salivary cortisol level is elevated, the excess cortisol is likely due to abnormal increased ACTH production by the pituitary or a tumor outside of the pituitary, or abnormal production by the adrenal glands. Additional tests will aid in determining the root of the problem.
If the person examined responds to an ACTH stimulation test and has insufficient cortisol, the problem is most likely due to insufficient ACTH production by the pituitary. If the person does not respond to the ACTH stimulation test, the problem is most likely to be with the adrenal glands. Secondary adrenal insufficiency occurs when the adrenal glands are underactive as a result of pituitary dysfunction and/or insufficient ACTH synthesis. Adrenal injury causes decreased cortisol production, which is referred to as primary adrenal insufficiency or Addison disease.
Once an irregularity has been found and linked to the pituitary gland, adrenal glands, or another source, the health practitioner may utilize additional testing, such as a CT scan, to determine the extent of any gland damage.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.