Thyroid UK
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My Thyroid 12 vacutainer test kit is finally here but what's the best time etc to test???

Hello you wonderful lot,

I'm not sure if this is featured somewhere else on the forum and I apologise if it is, but what is the optimal time etc for the thyroid test?

My last two have both been while fasting, but I've read that for a low TSH to genuinely appear that fasting increases your TSH and I'm wondering if it'll also impact all the other T tests etc?

Also, my last two were in the morning but with this test I can choose what time of the day to have blood taken.

Any insight would be greatly received as since I've been on the 70ml propranolol I am functioning better, well I can make it to the sofa and to the loo 20 times a day if that's functioning, but this blood test is desperately important as my marriage and home life is honestly hanging in the balance now if I don't get a realistic blood result.

That's not to say it has to be thyroid, it might be a million other things, it's just to say I want to do everything I can, to help my blood give me answers to why I'm so ill I'm going to lose everything.

3 Replies

The same applies MrsJim . If you are looking for a diagnosis of hypothyroidism then your TSH has to be as high as possible and that will be by a fasting, early morning test.

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Thank you for replying. I have hyperthyroid symptoms as does my mum and granny...

So it's dropped from 2.5 to 1.16 in five years but my symptoms have worsened as the TSH has dropped.

I'm having the full thyroid test next week but just need to know how to ensure I don't over inflate my TSH or any other levels if that makes sense?

Thanks again


Oh sorry, I thought you wanted a diagnosis of hypo so needed a high TSH. TSH will be lowest during the afternoon, also drops after eating I believe. That may be your best time then.

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