B

lood tests

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a work in progress.

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rt3adrenals@att.net

with corrections or comments

Cortisol blood tests are not useful in adrenal fatigue

• Measures the amount of cortisol only at one moment in time

• No information regarding the diurnal curve of cortisol

• Measure both bound and unbound cortisol (<90% is bound and

unavailable)

• Can be elevated by the stress of the blood draw

• Of value only if low enough for a diagnosis of Adrenal Insufficiency

Accurate ACTH levels are elusive

• ACTH levels fluctuate widely day-to-day

Samples must be

• collected in prechilled EDTA tubes

• transported in an ice bath

• receive prompt refrigerated centrifugation and plasma separation

TSH (thyroid stimulating hormone)

• Only of value when very high

• Controversy over the correct upper end of range: 4.5, 3 or 2.5

• TSH is suppressed by use of T3 medication

• TSH is suppressed by some common medications such as metformin

• TSH is correlated with only pituitary T3 levels

• The deiodinase enzyme which controls thyroid hormone in the

pituitary is different from the deiodinase enzymes which control thyroid

activity in other parts of the body

• TSH is not accurately correlated with tissue T3 levels when any of

these exist:

• obesity

• physiologic or emotional stress

• depression

• insulin resistance

• diabetes

• aging

• calorie deprivation

• inflammation

• iron deficiency

• low testosterone levels in men

• high levels of exercise

• pain

• PMS

• chronic fatigue syndrome

Read more about the science of why TSH is not reliable

at the National Association of Hypothyroidism website