U.S. doctors online nowAsk doctors free
Canada
A 41-year-old female asked:

Why are saliva and urine tests for cortisol only valid for high cortisol? why don't endocrinologists feel saliva testing is valid for low cortisol?

2 doctor answers3 doctors weighed in
Dr. Ed Friedlander
Pathology 45 years experience
Because it's not: There is a "pop" school of independent medical thought that holds that people who feel somewhat unwell have "hypophyseal-pituitary-adrenal axis syndrome" / "adrenal fatigue" and will screen for this on a spot salivary cortisol & Rx some herbals or vitamins. The danger of this hokey diagnosis is that you'll miss a real explanation -- emotional or physical -- for your symptoms.
Dr. Ed Friedlander
Pathology 45 years experience
Provided original answer
Any first-year medical student can explain -- cortisol in saliva is generally very low as there's little spillover if blood levels are near normal & most cortisol is bound; same applies with urine. Even Dr. Weil agrees http://www.drweil.com/drw/u/QAA401226/Are-Saliva-Tests-Any-Good.html
Jun 16, 2014
Dr. Steven Ferguson
General Practice 36 years experience
Saliva test helpful: Saliva testing is very helpful throughout the whole spectrum for your cortisol levels. Certain laboratories have a greater reputation than others. Saliva testing is also very helpful in evaluating your hormones such as estradiol testosterone and progesterone. The lava testing tests the amount of free hormone in your body. https://www.youtube.com/watch?v=pTJTeYEeSe0
Last updated Nov 24, 2018

Disclaimer:

Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.