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Thyroid UK
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Blood results

Just had results and need a little help deciphering what they means please TSH 0.09 T4 25.5 AND T3 3.7 Been on levothyroxine 150mcg and been told to reduce to 100mcg. Yet on 100mcg thyroid was still underactive. Waiting on a call back. Although the consultant actually told me to reduce my carbimazole which I have taken for 2 years.... First time I saw this doctor too. Any help would be appreciated

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If you could put the ranges beside your results it would be helpful as labs differ. To Edit, click on the down arrow.


Thanks for tge reply.

That's all it actually says and being told too reduce meds, waiting on a phone call lol


He has told you to reduce your dose because your TSH is low. He has ignored the fact that your T3 looks too low which will mean that you will probably get additional symptoms.

They shouldn't adjust according to the TSH alone.

Tell him you've taken advice through the NHS Choices for information on thyroid gland (Thyroiduk.org.uk) but before you reduce you need to know both the Free T4 and Free T3, the FT3 being the most important as our bodies need T3 to function normally. (this is an extract from the link below and it is important - unfortunately few doctors know about T3 or its action in our body).


T4 converts to T3 and is the only thyroid hormone actually used by the body's cells.

The approx. reference range for Free T3 is 4 to 8.3

We at Thyroid UK believe that you need to know your Free T3 level too because this will often show low if you are not converting, and high if you have blocked receptor cells. Even if you are converting, the body needs the extra T3 that a normal thyroid produces. There has been some research to show that people feel better on a mixture of Thyroxine (T4) and Triiodothyronine (T3). Effects of Thyroxine as Compared with Thyroxine plus Triiodothyronine in patients with hypothyroidism – The New England Journal of Medicine Feb.11, 99 Vol. 340


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Someone who is/has been hyperthyroid will respond re Carbizamole as I'm not sure why you're taking it as well as levothyroxine. I am not medically qualified so hopefully someone can enlighten me.



Are you taking Carbimazole and Levothyroxine (block and replace) for hyperthyroidism?


No not taking both, stopped carbimazole over a year ago, had radioactive iodine treatment, thyroid went underactive within a month, consultant said I am within the normal range for t3, over for t4, told her it will go straight back down within a month and bloods will come back as being underactive. First time I saw this consultant. Got to have another blood test in 6 weeks time and reduce levothyroxine to 100mcg, instead of taking 150mcg.


Hi Rach47 why is consultant asking you to stop taking carbimazole if you haven't taken it for a year?, Sounds like they haven't read your notes properly, or they don't know what they are doing.a drop of 50mcg is rather alot at one time, how are you feeling, do you feel hyper? If so maybe you could ask for a smaller drop say25mcg and see how you are on that. If you were hypo on 100mcg before why do they think it will be different this time! It doesn't make sense, you must be pulling your hair out in frustration.

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When I spoke to her she said it was a clerical error, no it was her error. No I don't feel hyper, but most symptoms have disappeared. I asked her to drop it by 25mcg but she said no has my t4 is now high and I am at risk of complications. I don't get it myself but if old symptoms return I shall complain. Will keep you posted.


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