I've got a phone consult with my GP this afternoon who always seem open to discussion, but is I suspect not the most clued up about thyroid stuff (and would probably admit it). Is there a simple way to describe the roles of those 3 results so I can have a conversation and feel like I know what I'm talking about?
Also, any thoughts on the below results?
My latest results are:
TSH: 0.181 (0.27 - 4.2)
FREE T3: 3.89 (3.1 - 6.8)
FREE THYROXINE: 15.4 (12 - 22)
As my TSH is technically low, and neither t3 or t4 very high in range, is there any argument for taking t3 being of benefit? I don't feel great (though have felt much worse). B12, D and Ferritin are good (though D at 85 maybe could do with help).
TSH is a message from your pituitary to your thyroid to produce hormone. If you don't produce enough, TSH goes up, which is why a high TSH is the primary diagnosis tool for being hypo. But TSH isn't itself a thyroid hormone. And it doesn't necessarily correlate that a low TSH means you are making enough thyroid hormone - the thyroid may not do what the pituitary is telling it [eg central hypothyroidism] - and anyway once you are on thyroid meds, there is a disconnect between TSH and actual thyroid hormone levels in your body, which is why TSH is pretty useless as a measure once you are on medication . And especially once you are on lio (T3 meds) - as this then suppresses TSH even further - it's just what it does.
Free T4 is the inactive thyroid hormone produced by the thyroid. It converts to free T3, the active thyroid hormone, which is needed in every cell in your body - your brain in particular needs a LOT. So testing free T4 is a start in working out if you have enough thyroid hormone, but doesn't tell you if you convert well enough, which is why, for a lot of us, free T3 is actually the most important test.
Everyone is different, but most of us hypos need TSH to be less than 1 and free T4 and free T3 to be in the top third - often the top quartile of range, Your results are 34% (free T4) and 21%. So both are too low, and you should ask for an additional 25 mcg of levo.
You only need lio if you are a poor converter - eg free T4 is very high in range or over-range and free T3 is still languishing at less than half-way. Your results are both so low at the moment, I don't think you can tell how good or bad your conversion is. But I 'm not surprised you feel less than great with such low results.
TSH is a pituitary hormone. It checks to see if the thyroid is making enough thyroid hormone.
If it detects that the thyroid is not making enough hormone it sends a signal and the TSH will be high - suggesting hypOthyroidism.
If it detects that there is too much thyroid hormone the TSH will be below range - suggesting hypERthyroidism.
TSH is useful for diagnosis of a thyroid condition. Once diagnosed and thyroid hormone replacement then TSH doesn't have such a useful role, it's the FT4 and FT3 that are important as they are the thyroid hormones.
T4 is produced naturally in adequate amounts a healthy person. In hypOthyroidism the FT4 level will be low. In hypERthyroidism the FT4 level will be high.
T3 is obtained by conversion from T4. Several organs in the body are responsible for this conversion.
If we convert T4 to T3 well enough our FT4 and FT3 levels will be fairly well balanced.
If FT3 is low in comparison to FT4 then that suggests we don't convert T4 to T3 very well.
The aim of a treated hypo patient on Levo, generally, is for TSH to be 1 or below with FT4 and FT3 in the upper part of their reference ranges, if that is where you feel well.
TSH: 0.181 (0.27 - 4.2)
FREE T3: 3.89 (3.1 - 6.8)
FREE THYROXINE: 15.4 (12 - 22)
Your FT3 is 21.35% through it's range.
Your FT4 (free thyroxine) is 35% through range.
is there any argument for taking t3 being of benefit?
Not at this point. You need to get your FT4 as high as possible in range by increasing Levo (despite your TSH already being below range). Once your FT4 is in the upper part of the range, see what your FT3 level is, if still low then it's possible you would benefit from adding T3 but you would need optimal nutrient levels first which are:
Vit D - 100-150nmol/L.
B12 - top of range (eg 1000pg/ml) for Total Serum B12, 100+ for Active B12.
Folate - at least half way through range.
Ferritin - half way through range.
If your GP is reluctant to raise your Levo, you can refer to the following from Dr Toft, past president of the British Thyroid Association and leading endocrinologist, who states in Pulse Magazine (the professional magazine for doctors):
"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l. In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l. Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l. This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l).*"
*He recently confirmed, during a public meeting, that this applies to Free T3 as well as Total T3.
You can obtain a copy of the article by emailing Dionne at
tukadmin@thyroiduk.org
print it and highlight question 6 to show your doctor.
thanks so much all. I probably need to look harder at my vitamin levels it seems - they are "in range" according to medichecks but obviously lower than they should be. And really useful re tsh/t3/t4 - thank you X
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High TSH but ‘normal’ T4 and T3
High TSH with Low T3 & T4
Low TSH with normal T3, T4. 
'normal' TSH and T4, low T3
Low TSH, normal T4 and T3
