Best Time of Day for Cortisol Tests

Okay, I asked this a few weeks ago with some saying that it is best to go as early as you can in the morning but someone on my last thread called Dee made a very good comment on the thread. She asked: "If your starting day is at 04:00, is a 09:00 cortisol test still accurate?"

This was the reason for my original question back along. Surely testing needs to be adapted to your natural rhythms?

My day starts late morning. Maybe one of the admins will clarify this.

Many thanks

33 Replies

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  • Foggymoggy, Cortisol and TSH follow circadian rhythms. Circadian rhythms fluctuate throughout the day/night but don't change according to the time you rise/retire.

  • OK thanks. I thought people had their own variations but obviously not.

  • Levels should be tested throughout the day, anyway, not just one test.

  • Unfortunately that's not an option.

  • So, what time are they testing it? If it's a blood test - the 24 hour test is saliva - it should be done at 8.0 am.

  • There's no way I can get there for 8 am. In fact I don't think they're even around that early. 9.30 am is the very earliest. Last time it was done just before 10 am and it was high.

  • Did they do anything about it? Because high cortisol is as bad as low cortisol - you need just the right amount. It's also a sign that your adrenals are getting fatigued and making a last ditch attempt to make enough hormone.

    I take it they have specific ranges for the time of day it was taken. Here in France, the test is called an '8 am Cortisol Test', and should be done at 8 am. But, although the labs open at 8 am sharp, it does depend on how many people manage to get there before 8 am, and there's usually a queue! Cortisol levels vary throughout the day, and that should be allowed for.

  • Oh I just made a comment further down about adrenals on the other thread! Yes, I thought the high Cortisol was to do with fatigued adrenals. They are going to repeat the blood test. It is due later this month but I've not booked it yet. It will be nearer the end of the month. I don't know what time the nurses start at our surgery but I'm guessing it's 8.30 or possibly 9 am. I think one GP I spoke to on the phone did say the earlier the better. My last one was at 10 am and for me that was a struggle to get down there at that time because it meant getting up about 8.30 am which for me is the middle of the night, lol

  • I understand. But sometimes a girl's gotta do what a girl's gotta do!

  • Greygoose is right. When I told my nutritionist I'd had a 24 hour cortisol test some months back and she found out I had the test whereby my urine was collected and added together In one container throughout the day, then sent off for an average result, her opinion was that it's not an accurate way to test.

    I believe she is going to get me to have different tests and I think she said a saliva swab done at varying times throughout the day will give a clearer picture.

    Hope that helps.

  • Hi thanks - as I said above I don't think that's an option unfortunately. I am being retested after 3 months. That is what they're offering me ie a blood test. Nothing said about saliva tests. With all the NHS cut backs it's getting to be more and more of a lottery :(

  • I agree NHS testing is a lottery. That's why Im getting my testing done through my nutritionist,privately.

    Wishing you all the best. Hope you get some answers soon.

  • Thanks choco. I have to get Cortisol retested this month. A I find it really hard to get up early and GP is a fifteen minute walk at least it probably won;t be much before 10 am.

  • Good question! I've often wondered about this. I often wake between 3 and 4 and sometimes get back to sleep but often don't! I did a Genova saliva test a way back but they give the times to do it. Even waiting for a day when I awoke at the time they were giving I wS not sure how accurate that was in the overall scheme of things! It's not easy to fit into boxes is it!

  • No! Thanks for your reply, Silverfox. I didn't realize you could get a saliva test. Is it very expensive and is it recognised by GPs? When I had my T3 and T4 done privately, they still took no action, even though one was just outside the range and the other on low side. I was told the one outside range was borderline and ergo no action required.

  • Can't remember the price-Google them but GP didn't want to know! Most likely as never been taught what should or shouldn't happen. Report from Feboca suggested another in a few months to rule out/or not being in free fall. I didn't bother as I thought it a lot of money if GP wasn't interested. Part of me thinks I should have done for my own peace of mind.

  • Thanks. The one I'm having done free will be a repeat so shall maybe see how that goes first!

  • Good plan!

  • I need a lot more than 8 hours. This is largely thought to be due to the lack of restorative sleep. I also need to sleep late afternoon/early evening. I hit a wall of fatigue and have learned to go with it

  • It's also due to being hypo - plus dodgey adrenals. Adrenals have a lot of effect on our sleep, one way or another. But we're all different.

  • Yes that's very true

  • Interesting! Thank you Grey. It's a fair point. I always say I listen to my body but in the sleep issue my temperature stays low if I don't sleep all night and my monthly heating bill is £184 so I'm juggling a lot of things at the moment! Also my son moans if he hears me moving about in the night! I can sometimes appreciate the gap in the night as a bit of me time but sometimes it can change into a bit of me worrying about something which is then counter productive.

  • Oh, that is so true! The brain tunes in to the wrong station, and there you are, at two in the morning, obsessing about something that happened 30 years ago! But, my theory is, that that is due to low T3 in the brain. Quite how that fits in with sleep patterns, I Don't know.

    Sometimes I sleep right through the night - not 8 hours, by any means - and Wake up early. Sometimes I Wake up after a couple of hours, go to the loo, and then Don't feel like going back to bed. So, I fire up the puter and do something constructive until I feel sleepy again - although I have been found sorting through my wardrobe at 2 am and trying on clothes! - and then I Wake up around 8 or 9. As I'm retired and live alone, that's OK, I can do as I please, but it must be difficult for other people sharing a house. Anyway, I now know not to fret about it. It's normal! lol

  • Well I was thinking yesterday upping my meds had meant I was sleeping better! Kiss of death that thought. Been awake since 4 so not too bad but ...... But forgot my square of salty chocolate!

  • Does a square of salty chocolate help? Sounds like a good idea, but good ideas Don't always live up to their promise. How are your adrenals?

  • Well! Told GP i was craving salt which I thought meant adrenals. She didn't offer to have me tested and saliva test not quite right but inconclusive I told new Endo who had already noted to send me for a short synathcen test and it was a disaster. Think I may have posted it already but got there far too early so standing out in cold. Set off any later wouldn't have go there in time-distance to travel etc and rush hour. Then was told they were expecting me the next day. They had given me a different day but still happy to do it but would have to wait for pathology to send request to see exactly what consultant had requested. That didn't arrive till 9.30 but she was so busy I had to wait for an hour then by the time is got a line in and looking like a pin cushion it was getting on even later and I left about 1pm! Normally I am good with needles but only one decent vein but I was so cold though they wrapped me up, hot chocolate and biscuits, heated pad, the works but told me although the timing a bit off consultant could work from a chart so no probs. was trying to stay calm but panic in hospitals. When I was sent for an WCG NEARLY KEPT ME IN BUT TRACE FINE, heart rate increased. So although results looked good not sure how valid they were! Sorry about caps-rushing (!) to go out!

  • Well, I doubt your GP would know that craving salt was a symptom of fatigued adrenals!

    The short synathcen test is a nonsense, because it will only tell you if you have Addison's or Cushing's. It's all black and white, with no grey areas that might suggest adrenal fatigue. So, if you haven't got Addison's or Cushing's, for them you're perfectly fine. How crazy is that!!!

  • Precisely! GP wouldn't entertain my testing and her suggestion I didn't think got off the ground plus I knew it was a waste of time!

  • Google has a better idea than most experts!!

  • I've not been diagnosed with hypothyroidism. I think I may have secondary hyperthyroidism. I have fibromyalgia. The stuff about the adrenals makes sense but have no idea where to start with that one. I think the Cortisol results may indicate something there? But although I don't sleep well, and often needing to wee in the night wakes me up, I never feel awake enough to go on a computer or out the light on and read if this makes any sense.

  • I've had the same question! My sleep has been very disrupted at times. Sometimes only being up for 8 hours or less.

  • Hope some of the answers others have given will help you too, SilverAvocado!

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