Thyroid UK

Just received my thyroid function tests and would like some help understanding them please guys


I asked my doctor to show me my last test results.. They were tsh 0.62 and T4 was 0.17.

I told her I'm struggling to loose weight and still have some symptoms so she is sending me for another blood test but has suggested I increase my meds from 125mg to 150mg as my tsh is showing a little room for change.

Can anyone provide some advice on what these level mean etc..

Many thanks



5 Replies

Hi Nadefc

Do you have the ranges of these as it will help some to comment. Labs differ in their ranges. It sounds like a good idea to increase your medication but the best way to know if they are working is the question 'how do you feel' and if 'fine' you are on a dose which suits you.

Before the TSH test came in, people were dosed on clinical symptoms until they resolved.


Your GP sounds very good. Some people find that they get their TSH within range (i.e around 4) but their GP won't increase their dose because they are in range! Your GP is right that there is room for an increase. There is no problem if your TSH goes below range because TSH doesn't correspond very well to thyroid hormone levels in hypothyroid patients. She would be better looking at your T4 and T3 levels.

Shaws is right that we really need reference ranges as they do differ from lab to lab, and the best way to know if you are on the right dose is to go by how you feel :)

As it sounds like you have a good GP, it would be asking for the following tests as they could be contributing to your weight and tiredness;

serum iron

ferritin (best 70-90 for most people)


vitamin B12 (if below 500mcg, consider supplementing with methylcobalamin form of B12)

vitamin D

Low levels of any of the above could be contributing to your symptoms (as well as needing more thyroxine) so it's a good idea to check them out. They can also affect how well your body is able to use the thyroxine you are taking.

I hope that helps :)

Carolyn x


Hi Carolynb..

I asked her about my T3 levels and she said the lab they use doesn't test it..

Not sure what to make of that?

She is also testing my B12 and folate, calcium profile and ferritin, and vit D but no serum iron... It that essential the iron serum test?

Thank you for your reply.. Most helpful and I really appreciate it...

Thanks Nade x


I think you could get a good idea from the tests you are having. If your ferritin is high, a serum iron test could be useful (to rule out a few things) but if it is low you know you need to supplement.

Your GP really does sound very good and I am impressed that she is doing all these tests. It really sounds like she knows what she is doing :)


Thanks Carolyn

I actually waited to get an apt with her instead of my original doctor as she helped me so much with something else a while ago which was a success..

Thanks for ur feedback on your opinions of my doctors investigations its helped heaps xxx

Nade xx


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