B

lood tests

to avoid

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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
• Measures 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
• receive prompt refrigerated centrifugation and plasma separation
• be transported in an ice bath
TSH (thyroid stimulating hormone)
• Of value only when very high
• Controversial regarding the correct upper end of range: 4.5, 3 or 2.5
• Suppressed by use of T3 medication
• Suppressed by some common medications such as metformin
• 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
• 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
here and here.