Blood Test Time: I have an appointment with my... - Thyroid UK

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Blood Test Time

Tristy profile image

I have an appointment with my Endo in the next few weeks and normally have the blood test straight afterwards. The earliest appointment I can get is 11.15 so the blood test will be about midday. I know not to take Levothyroxine that morning until after the blood test and also to fast from the night before until after the blood test. I am just concerned that the reading will be distorted as it's later in the day and I know TSH is highest in the morning. I could suggest I go back earlier the next day for the blood test if it makes a difference. I would welcome any advice please.

3 Replies

I think going back the next day would be the best idea, if your endo is overly concerned by the TSH. Because it will be lower than first thing in the morning. It won't affect the FT4, but will affect the FT3, but can't remember if it will be higher or lower. Best to be safe and go back the next morning. :)

Tristy profile image
Tristy in reply to greygoose

Thanks greygoose.

greygoose profile image
greygoose in reply to Tristy

You're welcome. :)

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