Cortisol Test

    Learn more about our Patient Engagement products now! Turn your patients into active participants in their healthcare by giving them easy access to the same evidence-based information you trust – but delivered in an easy-to-understand format.

    Cortisol Test

    Cortisol Test

    Why am I having this test?

    Cortisol is a hormone that plays an important role in many bodily functions. It helps regulate blood pressure and blood sugar (glucose) levels, aids digestion, and triggers the "fight or flight" reaction that your body uses to respond to stressful situations.

    You may have a cortisol test to check for problems with the glands that are associated with cortisol production (pituitary gland and adrenal glands). This test may be done to help diagnose these conditions:
    • Hypopituitarism.
    • Acute adrenal crisis.
    • A tumor of the adrenal gland.
    • Cushing syndrome or disease.
    • Addison disease, also called adrenal insufficiency.

    What is being tested?

    This test measures the amount of cortisol in your body.

    What kind of sample is taken?

    This test may be done using a sample of blood, urine, or saliva. Cortisol levels will vary throughout the day. Your health care provider may ask that cortisol tests be taken at different times of the day. One or more tests may be done to confirm results.
    • The most common way to measure cortisol in the body is to measure it in the blood. Blood samples are usually collected at 8:00 a.m. (when cortisol is highest) or at 4:00 p.m. (when it is lower). In some cases, it may be taken at midnight when cortisol is lowest. A blood sample is usually collected by inserting a needle into a blood vessel.
    • Saliva tests are usually done around midnight. This is done by swabbing the inside of your cheeks with a cotton swab.
    • Urine samples might include only one sample, or you may be asked to collect all of the urine you produce during a 24-hour period.

    How do I collect samples at home?

    You may be asked to collect urine at home, possibly over a period of 24 hours. Follow instructions from a health care provider about how to collect the sample.

    When collecting a urine sample at home, make sure you:
    • Use supplies and instructions that you received from the lab.
    • Collect urine only in the germ-free (sterile) container that you received from the lab.
    • Do not let any toilet paper or stool (feces) get into the container.
    • Refrigerate the sample until you can return it to the lab.
    • Return the sample to the lab as instructed.

    How do I prepare for this test?

    How you prepare for this test depends on what kind of sample will be taken.
    • If you will have a blood test, you may be instructed to:
      • Avoid exercise that takes a lot of effort (vigorous exercise) before the test.
      • Avoid stress before the test.
      • Stop taking certain medicines. These may include:
        • Certain anti-seizure medicines.
        • Androgens.
        • Estrogen.
        • Glucocorticoids (cortisone).
    • If you will have a saliva test, follow instructions from your health care provider about when to stop eating, drinking, and using toothpaste before the test.
    • If you will have a urine test, no preparation is needed.

    Tell a health care provider about:

    • Any allergies you have.
    • All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
    • Any blood disorders you have.
    • Any surgeries you have had.
    • Any medical conditions you have.
    • Whether you are pregnant or may be pregnant.

    How are the results reported?

    Your test results will be reported as a value that tells you how much cortisol is in your body. Different units may be used for blood, saliva, and urine.

    Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges also vary depending on the sample:
    • Blood:
      • Adult: morning blood test (8:00 a.m.): 5–23 mcg/dL.
      • Adult: evening blood test (4:00 p.m.): 3–13 mcg/dL.
      • Child 1–16 years: morning blood test (8:00 a.m.): 3–21 mcg/dL.
      • Child 1–16 years: evening blood test (4:00 p.m.): 3–10 mcg/dL.
      • Newborn: 1–24 mcg/dL.
    • Saliva:
      • 7:00 a.m. to 9:00 a.m.: 100–750 ng/dL.
      • 3:00 p.m. to 5:00 p.m.: less than 401 ng/dL.
      • 11:00 p.m. to midnight: less than 100 ng/dL.
    • Urine:
      • Adult: less than 100 mcg per 24 hours.
      • Adolescent: 5–55 mcg per 24 hours.
      • Child: 2–27 mcg per 24 hours.

    What do the results mean?

    Results within the reference ranges are considered normal.

    A cortisol level that is higher than normal may mean that you have:
    • Cushing syndrome.
    • Tumors near the pituitary gland or on an adrenal gland.

    A cortisol level that is lower than normal may be caused by:
    • Addison disease.
    • Certain medicines, such as chemotherapy and glucocorticoid medicines.
    • Hypopituitarism.

    If you have an abnormal result, you may need more than one cortisol test because cortisol levels can vary throughout the day and affect your test results.

    Talk with your health care provider about what your results mean.

    Questions to ask your health care provider

    Ask your health care provider, or the department that is doing the test:
    • When will my results be ready?
    • How will I get my results?
    • What are my treatment options?
    • What other tests do I need?
    • What are my next steps?


    • A cortisol test may be done to check for problems with the glands associated with cortisol production (pituitary gland and adrenal glands).
    • This test may be done using a sample of blood, urine, or saliva.
    • A cortisol level that is higher than normal can be seen in Cushing syndrome and in adrenal or pituitary gland tumors.
    • A cortisol level that is lower than normal can be seen in Addison disease, with use of certain medicines, and in hypopituitarism.

    This information is not intended to replace advice given to you by your health care provider. Make sure you discuss any questions you have with your health care provider.

    Small Elsevier Logo

    Cookies are used by this site. To decline or learn more, visit our cookie notice.

    Copyright © 2024 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

    Small Elsevier Logo
    RELX Group