TSH query

[Sunflower1-]

Hello again,I've just been scrolling on the web as you do and I have just read that-having a suppressed TSH whilst on medication does not make you hyperthyroidism.Is that true?you see my TSH is now at 4.82 and I've just been prescribed an extra 25mg of levothyroxine (making it 100mg now)but I was worried that what if I end up with no TSH because it seems that every 25mg dose increase I go down by roughly 7 numbers(if you get my drift).I'm sorry if I'm asking or saying anything extremely stupid or idiotic,I'm still new to this and obviously like to get myself worked up about things I do not completely understand.Again thank you everyone that always takes time to answer and reassure me,without you my head would be spinning for days on end.

[tattybogle]

hi , just because 25mcg reduced TSH by 7 , it doesn't follow it will do that again , the regulating system for TSH/ fT4 level is way more complex than that, so....

a) don't make any assumptions about what will happen to your TSH as a result of this increase . the only way to know how much it will lower your TSH is to try it and see.

b) if TSH is nearly 5 again, then that is a very good indication that 75mcg is definitely not enough for your body's needs so you definitely need an increase in dose and 25mcg is perfectly reasonable given how high TSH is.

c) even if 25mcg increase did send your TSH below range ( which is unlikely), it is not a problem in the short term .... below range TSH on levo doesn't make you "hyperthyroid", it just means the dose is perhaps a little more than you need and if so the solution is simple , just reduce dose very slightly and retest , no harm done . TSH will then come back up a bit .

Being slightly overdosed for a long time might / or might not cause symptoms similar to hyperthyroidism , and would increase the risks that are associated with hyperthyroidism, ....but a slight overdose is not a concern for the few weeks it takes to find out the effect of a new dose on your TSH / and ft4 levels .... at worst you might feel a little bit overmedicated for a few wks if the new dose is a bit too much , but with TSH currently over 4 and with a small 25mcg increase it's absolutely nothing to be scared of , honestly .

if it is really worrying you , you could increase by just 12.5mcg for 6 wks and then retest/ see how that feels before deciding whether you do need the full 25mcg .

it's very important to understand it's not the TSH level itself that causes any problems , it having too much or too little thyroid hormone (T4/T3). so don't let TSH scare you , pay more attention to how you feel and what your T4/ T3 levels are . and then look at TSH after that .

[greygoose]

Yes, it's true. The TSH is just a very rough, unreliable guide to thyroid status. It isn't even a thyroid hormone, it's a pituitary hormone. When the pituitary senses that there's not enough thyroid hormone in the system it increases TSH to stimulate the thyroid to make more hormone through what is called the HPT axis. And when thyroid hormone levels increase, the pituitary reduces TSH output. And this system works very well in a healthy person. But when you're hypo, the HPT axis can become warped, and the pituitary can cease to function on all cylinders.

So many things can affect TSH levels, like time of day, drinking coffee, takiing T3, having some sort of bug, or low nutrients, etc. etc. etc. Doctors are totally wrong to rely so heavily on it. And when it's the only thing that's tested, it doesn't tell you much at all.

Also, if you are hypo, you cannot become hyper, it's a physical impossibility. A sick thyroid, that struggles to make enough hormone, cannot suddenly recover and make too much just because the TSH drops. In fact, the thyroid cannot make hormone at all without the stimulus of the TSH.

What makes you hyper is very high Frees. And if your Frees are very high, over-range, obviously your TSH is going to drop. But it's not the low TSH that makes you hyper, it's the high FT4/3.

But all that is without taking Hashi's into consideration. Do you have Hashi's? With Hashi's, where the immune system periodically attacks the thyroid, your Free levels can swing between hypo and hyper levels. But that's not because your thyroid is over-producing, it's because the stock of previous-made hormone is leaking into the blood. It's only temporary and not true hyperthyroidism. But a lot of people/doctors don't understand that. And, of course, as I said, if the Frees rise, the TSH will drop.

With a TSH over 4 you certainly needed that increase in dose. All things being equal it should come down to 1 or under on thyroid hormone replacement. And yes, it might go below range, but that really doesn't matter. It's irrelevant. You don't need it when on thyroid hormone replacement because your thyroid is no-longer working. And TSH isn't needed for anything else. So, don't worry about it. Your doctor might! Bu you shouldn't.