# What is a TSH Rfx on Abnormal to Free T4 test?



## Whippetcat

Hi, I am a Graves' patient, who has relapsed, currently on Methimazole until I have my surgery to remove my thyroid in December. My doctor proclaimed my levels as 'good' when I had my last blood test (on 10-31-11). He ran the usual liver testing that is done when on Methimazole, and ran the test entitled TSH Rfx on Abnormal to Free T4:

My results for that were:

3.180 <0.450-4.500)

I am unsure what this test (TSH Rfx on Abnormal to Free T4) is? Is it a FT4 test? I have also had "plain, ole" TSH testing in the past, at the same time as this test, so I'm thinking this IS a FT4 test. Can someone clarify for me?

Please see my second post about what levels I should expect to feel good at post-surgery, thanks.

Roberta


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## Andros

Whippetcat said:


> Hi, I am a Graves' patient, who has relapsed, currently on Methimazole until I have my surgery to remove my thyroid in December. My doctor proclaimed my levels as 'good' when I had my last blood test (on 10-31-11). He ran the usual liver testing that is done when on Methimazole, and ran the test entitled TSH Rfx on Abnormal to Free T4:
> 
> My results for that were:
> 
> 3.180 <0.450-4.500)
> 
> I am unsure what this test (TSH Rfx on Abnormal to Free T4) is? Is it a FT4 test? I have also had "plain, ole" TSH testing in the past, at the same time as this test, so I'm thinking this IS a FT4 test. Can someone clarify for me?
> 
> Please see my second post about what levels I should expect to feel good at post-surgery, thanks.
> 
> Roberta


TSH w/ Reflex Free T4- Thyroid Stimulating Hormone - This test is used to identify hypothyroidism and hyperthyroidism. TSH is also useful to monitor thyroid hormone replacement therapy. Abnormal TSH levels should be followed by a Free T4 test, since Free T4 is more specific than TSH and serves to confirm thyroid dysfunction.

The above just means that the FREE T4 is more accurate in verifying the results of the TSH either way i.e. hyper or hypo.


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## Whippetcat

Andros said:


> TSH w/ Reflex Free T4- Thyroid Stimulating Hormone - This test is used to identify hypothyroidism and hyperthyroidism. TSH is also useful to monitor thyroid hormone replacement therapy. Abnormal TSH levels should be followed by a Free T4 test, since Free T4 is more specific than TSH and serves to confirm thyroid dysfunction.
> 
> The above just means that the FREE T4 is more accurate in verifying the results of the TSH either way i.e. hyper or hypo.


*Ok, then is NOT a Free T4 test, correct? And how does this test differ from a simple TSH test?*


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## Andros

Whippetcat said:


> *Ok, then is NOT a Free T4 test, correct? And how does this test differ from a simple TSH test?*


The way I understand it, they did do a Free T4 test to confirm the TSH indicating in your case hypo? If I am following this correctly, your FREE T4 was probably low confirming the hypo status.

AACE recommends 0.3 to 3.0.

See if there are any others out there who interpret this differently. I could be wrong.


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## SnoodMama

Maybe it means that they first do a tsh test and if it comes back normal, they stop there. But if it does come back abnormal, they then do a FT4 test??? Just a guess.


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## Andros

Whippetcat said:


> *Ok, then is NOT a Free T4 test, correct? And how does this test differ from a simple TSH test?*


Ask your doctors; that would be best and share w/us because we all like to learn these things.


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