Blood Tests - What could they mean: Hi I wonder... - Thyroid UK

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Blood Tests - What could they mean



I wonder if any of you could give me some advice on my first blood test results please?

Serum free T4 - 10.3 pmol/L (12.0 - 22.0)

Serum TSH - 1.83 miu/L (0.35 - 5.5)

Does this point towards a pituitary problem, if so how do I get this diagnosed/treated?

My mother was under-active but I don't know the reason why, I have a lot of the under-active symptoms and would like to start levothyroxine to see if things improve but doubt whether the doctor would prescribe for me.

I've just had another blood test for the above but dont have results yet.

Any help would be really welcome.

Thanks in advance for your time.


3 Replies

From you above tests I would say you are hypothyroid, due to the fact that your FT4 is below normal range.

Your TSH is rising but your GP may not diagnose you because your TSH is low (but check the above second link). Because your FT4 is below range you need to get levothyroxine as you don't have sufficient in your blood to convert to T3 and it is T3 which is needed in our receptor cells for us to function normally.

If you look down the left hand side you will also find more information as we need to read/learn/collect knowledge if we want to feel much better because the more we learn the more we discover doctors or endocrinologists know much less.

If GP hasn't tested thyroid antibodies ask for these too, as well as B12, Vit D, iron, ferritin and folate.


You really need t3 tested.My results I posted on here yesterday show why - my t4 is low, my tsh is very low - but t3 spot on. So all is well.

That's the active hormone and the most important one to get in range.

DebbieBrayBrook, your GP should consider secondary hypothyroidism which presents with low-normal TSH and low FT4. Secondary hypothyroidism is usually managed in endocrinology as pituitary function needs checking in case other hormones are also deficient.

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