Advice on which blood test to confirm T4 to T3 conversion.

[Occamoo]

Hello

I am hoping that someone here can assist me please. I am looking to have a private blood test to check that the thyroxine I take is converting to T3 and I am unsure exactly what test I should be requesting ( on the Blue Horizon site) to find the answer.

My history is a TT 12 years ago. I am now 40 years old. I Have always had symptoms of hypo ie fatigue, acne, unable to shift weight gain, digestive problems etc etc. I take 125/150 mcg thyroxine alternate days. My latest blood tests results are

Dec 13. TSH 0.09 ( range 0.3-4.2)

March 14 TSH 0.05 (range 0.3-4.2)

My GP wanted to reduce thyroxine at the first test but I resisted knowing how poorly I've felt on 125mch daily. She agreed to the further test in March, she deemed this as normal result. They are not willing to check anything other than TSH hence me going it alone.

I hope someone can give me a bit of assistance.

Thank you

Samantha

[Aurealis]

Hi Occamoo, I just wonder what your GPs explanation is for the shift in your test results? It's results like these and interpretations of them like you've experienced that destroyed my faith in the TSH test (for me, at any rate) many years ago. I have to say that I increased my thyroxine until I felt well but I know things can be more difficult now and there are the risks of suppressed TSH too. Before going it alone, I would have increased dose and gone back for another test and confessed, and hopefully demonstrated how well I was. The TSH test is not intended to be used to adjust dose, I understand, adjustments should be according to how you feel, so it sounds to me that your doctor may not be doing it right. I'm sure someone will be able to post some useful links for you. Most people can get well on Levo if they take enough. For those that can't then NDT /T3 can be a lifeline, but I wouldn't go that way unless you have to. You don't know what your free T4 or free T3 is so I suppose this would be a good place to start if you want to. I once reduced my thyroxine dose and my tested T4 increased! It's all so complicated.

[Hennerton]

I think it would help if you could have a free T4 and free T3 test. When I eventually insisted on this, after years of feeling unwell following TT, the tests showed that my T4 was above the reference range and the T3 was below. In other words I was not converting T4 to T3 and it was back stacking in my blood, making me feel very unwell. There may be an actual test to show this but I do not know it. Hope someone else will come along with the answer. The fact that your TSH is low is not because you are symptom free and normal, as GPs would have us believe but because the unconverted Levo is fooling your pituitary into thinking all is fine. At least that is what I believe to be the case. Can anyone add to that?

[Heloise]

Samantha, I'm sorry you have such a negligent system for thyroidism in the UK. Hennerton made good suggestions. It would be wonderful if you could get those FT3 and FT4 tests done. I wish all could start with a natural desiccated hormone so we would have a better idea of where the fault lies but if it is a case of your thyroxine turning into reverse T3, you could look at the first three links at the top of the page and see if it relates. thyroid-rt3.com/backgrou.htm

[shaws Administrator]

I am glad you persuaded your GP not to reduce your meds, according only to the TSH result as this can have an adverse effect but GP's don't understand.

After your blood test result, this link on vitamins may be helpful, particularly the last 3

thyroiduk.org.uk/tuk/treatm...

[Occamoo]

Thank you for your responses. I shall be reading the links you have given this afternoon. I have to admit that I don't think any GP I have ever seen has even mentioned vitamins to me.