New reference range for TSH

Morning everyone, two months ago my TSH level was 5.1 ( 0.5-5.0) and was termed as sub clinical hypothyroid (borderline). I have learnt as of January 17, the lab has changed its reference range to 0.5-4.2.

Does this mean I know fall into the range whereby I might get medication from my gp ?

I am 60 years old and an under active thyroid runs down the female line in my family.

I have a lot of hypothyroidism symptoms and was now wondering, in light of this new information, how to approach my gp.

Any thoughts and advice from you would be appreciated.


25 Replies

  • Milpol You could try. If GP is hesitant you could ask for a new test so you have a result with the new range. Ask for FT4 as well, plus antibodies. And while they are doing those, Ask for

    Vit D




    If your GP is one of those who waits until TSH reaches 10 then you'll still get nowhere, but you can try.

    Don't forget to book the very first appointment of the morning and fast overnight (water only) to get the highest possible TSH.

  • Thanks Seaside Susie, much appreciated 😘

  • Milpol,

    No, if your original result fell 90% through range it should still be 90% through range in the new range.

  • Thanks Clutter. My battle continues then 😥

  • That would be true for FT4 and FT3, Clutter, but I don't think it works that way with TSH. TSH is TSH whatever the range. And a TSH of 3 is hypo, whatever the range - only doctors in the UK don't know that.

  • Thank you Greygoose. This has made me feel more hopeful. I'm going for my second test tomorrow. That will check my antibodies and hopefully my TSH again. I will post results. Thanks for your response 😘

  • Milpol,

    It's protocol to ignore the first abnormal TSH result and retest 2-3 months later as TSH can be elevated by a virus or infection which would be expected to resolve within 2-3 months.

    Make sure your blood draw is early in the morning when TSH is highest and fast (water only) because TSH drops after eating and drinking.

  • Thank you Clutter, I will. My last result back in Dec , was taken after lunch and I'd had my breakfast and 2 cups of tea ! In December I was a total Thyroid virgin and knew only what my gp told me to do, and that was ' no need to fast and don't go before lunch as you will only have to wait ages as all the cholesterol testing takes place first thing ' .

    Thanks to all you wonderful people who respond to people's issues, I have learnt so much and am going into this second blood test with much more knowledge.

    Thank you 😘

  • Milpol,

    TSH 5.1 would have been higher had the blood test been done as an early fasting test. Good luck this time!

  • Thanks. Will post when get new results 😘

  • don't go before lunch as you will only have to wait ages as all the cholesterol testing takes place first thing

    That's ironic. It is being hypothyroid that raises cholesterol in the first place. Once people are on optimal doses of thyroid meds cholesterol levels drop.

    My surgery sends all blood samples to the pathology lab at my local hospital for testing. I can get blood taken either at my surgery with an appointment, or go to the phlebotomy department at my local hospital and get blood taken without an appointment. If you can do that you could decide when to get the blood taken yourself.

    Having said that, someone recently reported on here that their local hospital used to have the same arrangement as mine, but the hospital had now put a stop to it. :(

    I'm still waiting to find out if the arrangement has been stopped at my own local hospital.

  • The whole thing seems a bit of a farce ! I am so confused with it all. It's no wonder so many people have these issues ! It looks like thyroid testing and monitoring needs a major overhaul!

  • I can go to local hospital but only with a request from GP.

  • Greygoose,

    It will be true for TSH. If the range has changed it usually means the analysing machine is new or recalibrated and the population reference range has been reassessed.

  • Thanks Greygoose, I will post New results when I get them.

  • Sorry, I don't buy that. If that were the case, there would not be an international cry to lower the top of the range to 3/3.5. If that were the case, there would be an international cry for everybody to have the same machine. But there isn't. It is often stated that you are hypo when your TSH is at 3. One would not be able to say that if the range depended on that machine, it wouldn't be logical. And, if that were the case, one would not be able to say that TSH should be one or under, once on thyroid hormone replacement. A TSH is a TSH whatever the range.

  • Greygoose,

    Why bother to change the range then?

  • Could it be that they are becoming more enlightened???

  • In my view, the very fact that papers and guidelines refer to specific numbers undermines their credibility. Having a top-of-range at 3.0 would result in different people being under- or over-range depending on all the factors such as the manufacturer of the assay, the actual lab, etc.

    (Actually, not all TSH is even the same! In the hypothyroid state, not only do people produce more TSH, but a subtly different TSH that remains for longer in the blood.)

  • Plus the time of day the test was done. I don't see how you can have a fixed range when TSH varies throughout the day.

    I'll read the links tomorrow. But, the more you learn about it, the more rubbish the TSH test becomes.

  • Agreed.

  • If the reference range has changed it could be due to a method change within the lab and although your thyroid function may have deteriorated slightly more since your last test and therefore fall outside of the 'normal' range, you equally may have stayed the same and under the new method still fall just within the new 'normal' reference range. To be honest you won't know until you go and get a new test done. It is also all about your symptoms. Make a list, use the thyroid UK website, you can print a list of symptoms and tick the ones that apply to you. I say lay it on thick, but you know it isn't really when you feel so awful but you can't play it down with them (GP's) tell them as it is and then some. You may just get them to give you a trial on T4 .

  • Thanks. Will definitely try and give it a go. I have a lot of symptoms and feel rubbish with absolutely nil energy almost all of the time, so it won't be difficult to lay it on thick. Have the list ready and waiting! Wish me luck.

    Thanks for the advice. Much appreciated.

  • 😘 will keep you posted !

  • Good luck chuck, i know how you feel!!

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