Thyroid blood test

[SunnyK]

Hi,

Just a quick question about my blood test.

I have ordered the medichecks thyroid and vit blood test and having it taken at the hospital. I understand fasting and going first thing in the morning is best but what about my menstrual cycle.

I am day two, suffering terribly, so I know I have physical symptoms, will this also have in implication on my test results too. Any experience or advice welcome.

I have so many things wrong with me now that I have given up work. When I think I have progress with consultants it just flags up something else that they don’t understand and can’t treat me for. So I feel useless and unreliable. Always something wrong with me.

Sx

[jimh111]

Looking at some of your earlier results: -

TSH 2.51 (.5 - 5.0)

FT4 12 (12-22)

FT3 4.6 (3.1 - 6.8)

It woud seem that your TSH is too low given your fT3, fT4 combination. Having the blood taken early gives a TSH that is a little higher. TSH is also higher (to a greater degree) mid-cycle ncbi.nlm.nih.gov/pmc/articl... . I've seen no good evidence that fasting makes any difference.

So, to answer your question mid-cycle early morning will give the highest TSH.

I would say you shouldn't seek a higher TSH, that the problem is the lack of TSH response to your low fT4. If (wrongly) diagnosed with primary hypothyroidism your doctor could give you a small dose of levothyroxine which brings your TSH down and say 'now you are cured'. I would focus your attention on your low fT3, fT4 and the failure of your TSH to eleavate appropriately.

[SunnyK in reply to jimh111]

Hi Thanks Jim,

Yes I see your point and didn’t realise that before, but as we all know getting any support or recognition of a problem relies on TSH which is why I initially thought my Low FT4 and 3 were unimportant. Anyway it’s a private test and I will take my results to a private specialist should I need to after receiving my results. They will hopefully see what you see and I may get some answers.

I just didn’t want to get it wrong and get untrue results according to my menstrual cycle.

Thanks for your quick response

[jimh111 in reply to SunnyK]

it seems that fT4 is not affected by the cycle so watch out for fT4 going low, it could be very helpful in getting a diagnosis (and arguing that TSH should not be used for monitoring treatment).