Issue

[Angelic69]

Hi all just a quicky. If high Tsh also is associated with low estrogen then once on replacement thyroid hormone hpw would you tell if oestrogen is low.And how without doi.g further test to establish if its thyroid or oestrogen do they put you on thyroid replacement when it could have been estrogen

[diogenes Remembering]

Oestrogen has a definite effect on levels of FT4. On the pill, the level is too low to have much effect, but in pregnancy, the effect is quite obvious. Also for men on prostate reducing therapy. But the answer is subtle. It's not the thyroid that is being changed, but the size of the openings in cells for T4 to get into the tissues to give suitable FT3. If you increase the openings, then you need less T4 to get through each of those increased openings to give you exactly the same T3 in there. It's like having doors. With a certain number of doors only a certain crowd can get through. That's enough to view what's inside without too many people in. Increase the number of doors, you could get more people in but that would crowd out what is viewed. So you lower the number of people going through each door to balance things out. That means for each door the pressure of the crowd has to be less. That is, a lower FT4 ensures the same overall entry of T4 into the cells.

[shaws Administrator in reply to diogenes]

That is a lovely explanation. Thank you

[diogenes Remembering]

Also I don't think high TSH is associated with low oestrogen and I don't know the statement source that this happens.

[Angel_of_the_North]

It isn't always. I had low oestrogen, low progestrone and low TSH. Anyway the tests are quite separate, so if your sex hormones are low, those tests would show it.

[silverfox7]

I've an a similar conundrum. Can't work that out in my head imeither! Had breast cancer, estrogen doninent so taking medication to lower it so that makes sense but then I wondered how do I know it's working and not having anyone to ask I don't know is the simple answer. Mentioning TSH in the equation has I think now persuaded me to forget about it!!!! I can cope with the more simple life!