what time should blood be taken

[jazzanne]

f you work shifts and sleep 3am - 2pm does the 9am and 12am cortisol blood stay the same or should it be drawn at diff. times many thanks x

[shaws Administrator]

I'm sorry you haven't had a response yet. I have been trying to find out but so far I've had no luck. All it says so far that the cortisol is highest early a.m. but shift work could definitely affect it I feel sure.

[shaws Administrator]

This is an excerpt:

Shift work: nurses working on morning shifts with very early awakening (between 4:00–5:30 a.m.) had a greater and prolonged cortisol awakening response than those on the late day shift (between 6:00–9:00 a.m.) or the night shift (between 11:00 a.m.–2:00 p.m.)

and

Waking up in the light: cortisol awakening response is larger when people wake up in light rather than darkness.

So a guess is that you'd have to have a cortisol test as soon as after you awake.

en.wikipedia.org/wiki/Corti...