Thyroid UK

What do you think about 24hr urine tests for cortisol (adrenals) vs 24hr saliva cortisol tests?

My friend has been seeing a Harley St Endo who is reluctantly testing her adrenals. (There's a bit of a back story which Is explained following my last question the other day for those who want to read it!).

On my advice, she has asked for a 24hr saliva test (because it tests at 4 individual times of the day which gives a better reading as cortisol levels are naturally different at different times of the day). He won't do this and said that he's going to so 'something even better and more accurate' which is the 24hr urine test for adrenals. Now I've read, and this makes absolute sense to me, that this test isn't accurate because it combines all your urine in one sample, so if for example it's higher than it should be in the morning say, but lower at lunchtime, this test won't pick this up as it takes the average as it's all in one sample.

When I did the 24hr saliva samples, my cortisol and DHEA were below the norm in the morning, higher than norm at lunch and much higher than the norm at midnight. If it had been a urine sample I'd done, we wouldn't have known the true readings and I understand different levels at different times mean different things. (I can't remember what off the top of my head).

Just wondered what others think about the two tests and whether the 24hr urine one is accurate enough?

Thanks! X

3 Replies

So sorry you had no replies - it would appear that your question was missed...

Hopefully someone with relevant knowledge will pick it up from Latest Activity...




The 24 hour urine test has never made sense to me. As you have already commented - levels can be good at one part of the day, high at another time, and low the rest of the time. Once you merge all this together into one result it will just smooth out the information that is being measured and create a meaningless result.

And hey presto! A good way for a doctor to declare a sick patient is well. Luvverly jubberly. One happy doctor, and one miserable patient.

It makes me think of temperature data recorded for a desert at the equator. It might be 40C in the day time and 0C at night. This could be interpreted as an average of 20C for the entire day. Wonderful! I wouldn't even need a sun hat!

Sorry, I think my cynicism is showing...


Thanks so much for your reply Humanbean - it really made me laugh and is so true! It's crazy how they use such a test - do they have no common sense?!


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