The ZRT Laboratory Blog

The ZRT Blog is an extensive resource for patients and health care providers searching for health and hormone testing information. Here, you can read about ZRT’s cutting edge research, advances in testing, wellness advice, and health industry highlights.

How Reference Ranges Determine a "Normal" Lab Test Result

Posted by Margaret Groves on Friday, 13 November

'Abnormal' on a chalkboard with 'Ab' crossed out and 'Normal' underlinedCLIA-certified testing laboratories such as ZRT are required to provide reference ranges as an aid to interpretation of test results.

Ideally, reference ranges provide the expected range of values for a healthy population. When methodology and equipment is identical for testing a particular analyte among different laboratories, reference ranges for that analyte should be the same.

However, when methodologies or equipment for the same test differ somewhat from lab to lab, each lab must provide its own reference range established with its own methods. These ranges are usually very close, but may differ slightly depending on method. An example would be testing testosterone in blood or saliva by extraction and LC-mass spectrometry vs. direct testing by immunoassay.

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Cortisol Testing in Saliva, Blood & Urine

Posted by Dr. David Zava on Friday, 29 May

Patient collecting for saliva, blood spot, and dried urine testingPractice Takeaway: Providers should be aware that three different body fluids – saliva, blood or urine – can be used to assess adrenal gland function, and should know each method’s advantages and disadvantages, when deciding how to test patients.

Inadequate or excessive production or disrupted circadian patterns of cortisol synthesis by the adrenal glands in response to stressors can eventually lead to imbalances in blood glucose levels, impaired immune response, as well as a host of different hormonal imbalances, all of which are associated with multiple adverse conditions and symptoms.   

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How to Use a Symptom Checklist to Choose a Hormone Test

Posted by Dr. Sherry LaBeck on Tuesday, 12 May

Patient filling out symptom checklistSymptoms of hormonal imbalance can often be challenging to assess.

Is your patient exhibiting signs of estrogen dominance because her estrogen is too high or is it due to the progesterone being too low?

Is his fatigue because he’s not making enough testosterone or that his adrenal glands are working over-time?

Are her imbalanced sex steroids the cause of her depression or is it the low thyroid hormone?

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The Journey of a Saliva Test Tube

Posted by Jessica Strom on Thursday, 09 April


When ZRT Saliva test kits arrive at your practice or pharmacy, you probably aren’t wondering about the journey they took to get there. But what if you learned that along the way, their assembly created jobs for individuals with developmental disabilities?

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