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Problems Interpreting Cortisol Lab Tests in Adrenal Fatigue


October 8, 2009 | Published by

Complicating the problem of proper interpretation of laboratory data in adrenal fatigue is the fact that steroid hormones occur in more than one form in your body, but most lab tests measure only one. Cortisol, for example, takes on three forms in your blood: 1) unattached to any other substance (free), 2) loosely bound and, 3) tightly bound to blood proteins. The most common measurement for hormones is the amount of hormone not attached to anything, called the free circulating hormone.

However, this usually represents a meager 1% of the total amount of hormone available. It does not measure the bound hormones, which act as reserves and become free hormones if needed. This reserve can be critical to proper physiological function. For example, very low circulating cortisol levels can be brought to within normal range by the administration of a synthetic cortisol. But people taking synthetic cortisol cannot withstand stress as well as people with naturally normal cortisol levels, even though blood tests for both show normal free circulating cortisol levels.

One reason for this is that although free circulating cortisol levels are increased by taking the synthetic cortisol, levels remain low of tissue bound cortisol that provides reserve stores in cases of emergency (stress). Blood tests can often be deceptive because they do not typically give you the whole picture. Therefore, even though both healthy people and people taking cortisol might show normal free cortisol levels, their response to stress will probably differ considerably. The test results would give a very deceptive picture of “normal” in the case of the person receiving the drug, as it tests only the most superficial layer of cortisol availability.

In adrenal function, the extreme low on a bell curve is Addison’s disease and the extreme high is Cushing’s disease. The other 95% represents an enormous variation in levels of adrenal function that is usually disregarded by lab computers and overlooked by doctors because the scores in this range do not fall into either of the two extreme or “diseased” categories. By default, any scores falling within this range (95%) are considered “normal” The end result of basing laboratory test scores on statistics rather than on signs and symptoms is that many people who have mild to moderately severe adrenal fatigue are never accurately diagnosed; they look “normal” on the tests.

Stress is a factor that significantly affects adrenal hormone levels. Your cortisol level tested after a quiet, relaxing morning will be very different from your cortisol level tested when you are under stress before you arrive at the lab. To obtain a typical value, have your test on a typical morning.

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  • jenny says:

    Is it safe to take adrenal glandular extracts for those of us with a history of estrogen positive breast cancers? I know I should avoid DHEA but are there large amounts of sex hormones in the glandualrs?

    • adrenalfatigue says:

      Hi Jenny,

      The Adrenal Rebuilder is hormone-free and is designed to nourish the adrenal glands and promote natural adrenal health. As always, if you’re unsure, it is best to consult with your healthcare practitioner. Hope this helps – thanks for your question!

  • My husband recently had his cortisol levels tested by 24 urine test. I am having difficulty interpreting the results. I wonder if anyone could help. They are:
    24 hour normetadre output 1.02 umol
    24 hour urine metadren output 0.67 umol

    He suffers from depression and extreme anxiety.


  • Lynne says:

    I have every single symptom of adrenal fatigue given on multiple websites and I’ve had these symptoms for decades. I’ve also been on thyroid replacement since age 12 (Hashimoto’s) and I am now 50. My doctor just ran a morning blood cortisol and ACTH on me and both values were “normal.” The cortisol was 20.3 and the ACTH was 11.8. She then dismissed me. Can I have adrenal fatigue and still have these normal results?

    • adrenalfatigue says:

      Hi Lynne,

      It is possible, yes – Blood cortisol tests tend to capture a snapshot, so cortisol could be within the normal range at that time. A saliva cortisol test captures a spectrum over a day’s time, so you tend to get an overall picture of cortisol levels. More information on saliva vs. blood cortisol testing can be found in this blog entry as well:

      Hope this helps – thanks for your question, and best of luck!

      Dr. Wilson’s Adrenal Fatigue Team

      • Lynne says:

        Thanks so much for the fast reply! I will definitely look at the link you sent. I have a saliva test for cortisol and DHEA-S which I will do on Monday and send back to ZRT. I also did some reading about CBG and wonder if mine may be high due to high estrogen from perimenopause. Evidently high E2 causes the liver to produce more of this binding protein, which ties up the cortisol in the blood so it cannot get into the cells where it is needed. Is there a test for CBG?

        • adrenalfatigue says:

          No problem, Lynne! There are tests available for CBG, though we don’t have any preferred or recommended facilities for this test. As with any testing, do your research on the testing facility and/or healthcare practitioner analyzing the results. Best of luck!

          Dr. Wilson’s Adrenal Fatigue Team

  • scott says:

    My moring cortisol test came back almost twice the standard range…I feel I fit all the symptoms of adrenal fatigue…my dr said I cant have it because based on the cortisol test I cant be defiecent

  • scott frask says:

    I recently had pneumonia and had to go to the emergency room…I had a 104.6 fever..they gave me IV antibiotics and a corticosteroid shot…I have alot more energy in the past few weeks since I was sick and was wondering ifmthe antibotics or the corticosteroid has anything to do with it…

  • Amelia says:

    I had a blood cortisol test at 7am and the results were 33.0 ug/ml. I haven’t had a follow-up appointment with my endocrinologist yet. Are these results concerning?

    • Brandon Derrow says:

      Hi Amelia,

      Baseline values for a cortisol blood sample taken at 8 in the morning are 6 to 23 micrograms per deciliter (mcg/dL). Did you mean 33 mcg/dl? Morning results of 33.0 ug/ml would be quite low.

  • Matt says:


    How reliable is a 4 point cortisol saliva test in isolation?
    (and do benzos or medication impact results)

    And does it test only free cortisol or metabolized cortisol too?

    I have had AF for 2.5 years to varying degrees.
    In Sep 2016 I had a saliva cortisol test that looked flat. This came after a bit of a crash.

    I recently had a big crash and had another test done that fits right into the normal range, with the noon level slightly high.
    This confuses me.
    Intuitively I feel that I in no range could be over AF.

    Any thoughts?

    • Adrenal Fatigue Team says:

      Hi Matt,

      Dr. Wilson believes cortisol saliva tests to be the best measure of adrenal performance. For specific questions on saliva testing, we recommend contacting ZRT Lab. You can find their contact information on their website here:

  • Carolyn Schausten says:

    I recently had a 24 hr cortisol urine done. My level is 151 with the lab range between 58-403. I am experiencing a lot of symptoms similar to addisons disease. I seem to have about 7 hours of energy from waking and then I am completely exhausted. Exercise or exertion is out of the question as by the end I have nothing left for the remainder of the day. It is debilitating fatigue. I am the mom of four kids, two with special needs so my stress level is always high. I am unsure with the number if it really tells me anything. I am working with a functional medicine practitioner.

    • Adrenal Fatigue Team says:

      Hi Carolyn,

      Unfortunately we are not able to make any suggestions or advice based on lab results. Addison’s is quite severe and should be diagnosable by your health practitioner. Regardless of your diagnosis, if your stress level is high it could be beneficial for you to look at diet, lifestyle and supplementation changes to support yourself.

  • Jeannie says:


    I have hypothyroidism and ever since being diagnosed, I have had nothing but weight issues.
    Ive tried everything to lose, and not one great result.
    My doc sent me in for a Cortisol AM and the test came back 24.3UG Normal range 5.0-25.0.
    Can I still be suffering form this disease since I’m borderline? I have the fatigue, the lump and the moon face
    I’m soo lost ?

    • Adrenal Fatigue Team says:

      Hi Jeannie,

      It’s not unusual for cortisol levels to be in the normal range for one part of the day, but be off during other times. For example, your AM cortisol could be fine, but could be low or high mid-morning, at Noon, afternoon, and overnight. Cortisol fluctuates throughout the day, which is why Dr. Wilson recommends 24 hour saliva tests.

  • Panayiotis says:

    Hi!My saliva test show high cortisol afternoon evening and night.I need the adrenal herbal support formula with licorice or without??

  • Lauren says:

    There is conflict in two different Cortisol tests! Cortisol stimulation test at 8:30am shows a normal 30. Yet the Adrenal Hormone Saliva test sex Phase 3 Adrenal Dysfunction! cortisol AM30 was 4.9, Noon was 3.7, Eve was1.1, might was .44. DHEA is 138 and SigA is 367! How so? I’ve lived a long life of stress and anxiety and have much fatigue, insomnia and digestive disorders. Any explanation for the opposite test results? Tkd!

  • Mic says:

    Hi my cortisol level just came back at 8
    Is this concerning?

    • Adrenal Fatigue Team says:

      Hi Mic,

      We can’t say for sure, as we aren’t healthcare professionals. What kind of test was administered? At what time of the day is the 8 level assigned? What unit of measurement is used here when referring to 8? These answers would be helpful in determining if you should be concerned about your cortisol levels.

  • MaryLou says:

    Why is my endo. Dr. Concerned? I am hypothyroid since 19 years old. I’m now 71 and having problems. Had cortisol level done( 10.6 mcg. Normal right. Why is the doctor doing a different blood test and saying my levels are low?

    • Adrenal Fatigue Team says:

      Hi MaryLou,

      We get your frustration, but are unable to address the motives of your practitioners. Certain tests measure differently, which could be a factor. For example, cortisol blood tests and saliva cortisol tests work differently.

  • Charles says:

    I have recently had a Dexamethasone test done. 1mg at 11pm then blood work done at 8am.
    The results:
    Cortisol 2.7 ug/dl
    Acth, plasma 2.8 pg/ml
    Dexamethasone, Serum 264 ng/dl
    I have an adrenal adenoma.
    Are any of these concerns? They seem low and the Acth 2.8 pg/ml has been that low since 2017.

    • Adrenal Fatigue Team says:

      Hi Charles,

      We are not healthcare practitioners and are unable to provide medical advice. We do work with practitioners across the country and may be able to provide you with a referral. If you’re interested, write to us with your location at or call us at 800-357-5027. Thanks for writing!

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