Thyroid UK
84,238 members99,237 posts

Blood test

I have just received a letter from my GP asking me to go for a blood test. The form asks for results of just TSH only. Is this test any good?, last time I had a blood test they wanted to reduce my levo, but I later found out my GP hadn't seen the result, the Practice nurse had ordered the reduction! My GP confirmed that I stay on 125mgs. I think I might ignore the request as I feel wellish at the moment. What do you all think?x

8 Replies

I assume your doctor is doing an annual check on your TSH. This is the standard test for hypo patients but if they wanted to reduce your levo then I suspect they checked T4 as well. If this gets too high they are worried you might go hyper, which is worse than hypo. I would worry about a practice nurse reducing my levo, but if you have the test done make an appointment to see the doctor for the results and get a print off so you know what he is looking at if he wants to reduce your levo. If you feel well on 125mgs, stand your ground, its all about how you feel, not their results.


I don't really think you're quite right there, Jan. There is absolutely no reason to suspect they checked the T4 at all. Most doctors just go by TSH. And they are worried that if the TSH goes to low you will have a heart attack on the spot and your bones will crumble and disintegrate! lol

Hugs, Grey


Agreed. They only check my T4 because my TSH is always low. Out of range TSH is the only circumstance, most of the time, where they will check T4 unless you are very lucky.


The only reason I felt confident about the T4 was that when I got a print out of my results from my GP T4 was on it, sorry I didn't mean to mislead anyone, but thank you.

I am still on a learning curve, so please explain why a low reading of TSH alone would indicate an imminent heart attack or crumbling bones.

By low, is that below 1?

Thanks again


By low I mean below suppressed, 0.02 or something like that. Although the trend seems to be to keep the TSH higher and higher, so maybe they could be talking just about below 1. And it doesn't indicate an imminent heart attack or crumbling bones but lots of doctors think it does and use that as an excuse for keeping the TSH too high and the patient ill.

In the beginning - of blood tests - to find out if a patient had a thyroid problem, doctors would test TSH, FT4 and FT3, which all us patients agree are very necessary to get a clear picture - well, as clear as is possible.

For some reason which eludes me, laboratories took over the power of doctors and started refusing to do FT3 tests if the other two were 'in range' - a meaningless statement in itself. And, it would appear, their word was law and they could over-ride the instructions of doctors (not really sure why doctors, who consider themselves god-like, put up with this, but still...). (Actually, I think they only reason they put up with it is because they don't know how to read the other tests anyway.)

Now, it would seem, they are going one step further and refusing to do the FT4 if the TSH is 'in range'. Just what lab technicians know about the thyroid and its malfunction, I cannot say, but it would appear they think they know more than doctors - which admittedly isn't difficult, but still...

Just where all this will end, I really don't know. Perhaps they will start refusing to even test the TSH if there's an R in the month, or if the innards of the chicken they've just slaughtered indicate there is no need. Seems to me that anything is possible...

So, you had an FT4 test - at least, I hope it was an F, because sometimes they do the total and that gives you no useful information whatsoever - and it's good that you got it. But it isn't a given anymore. Unfortunately.

Hugs, Grey


Very enlightening but also a bit worrying. Who controls the labs, presumably the NHS? I haven't had a test for sometime but it will be interesting to see what they test for next time (I will be sure to avoid a month with an 'R' in it, just in case!!) .

Thank you so much, it has greatly added to my understanding.


Hi Dylansmum, the TSH is useless as a test! But here's a novel approach you could try. Go and see them and say you will have the test if they promise to do the frees and dose by the frees only, not the TSH. If they won't undertake to do that, say you won't have the test! Go on strike! Enough of this rubbishy TSH that is ruining people's lives!!!

Well, just an idea...

So who does that nurse think she is??? Reducing your levo off her own bat. And just on the say-so of a TSH, to boot! I'm glad you stood up to her. Very well done!

Hugs, Grey


TSH is a very accurate test... for measuring TSH levels. Unfortunately knowing your TSH level is as useful as a chocolate teapot for diagnosing and treating hypothyroidism.

There was some research in February that showed that TSH doesn't respond to thyroid hormone level in the way it should in hypothyroid patients and that hypothyroidism should be treated as a completely different entity to euthyroidism or hyperthyroidism. Basically TSH is useless unless you are euthyroid or, to some extent, hyperthyroid and even then it shouldn't be used without symptoms and T4 and T3 if you actually want to correctly diagnose and treat.

Here is a link to Rod's blog where he posts about this paper.

Keep standing your ground and stay away from that nurse ;)

Carolyn x


You may also like...