Had these 3 tests done. Please give opinion on results. TY

[Smile4U]

Free Thyroxine - 1.24 ng/dL (Reference Range: 0.78 ng/dL - 2.19 ng/dL)

Thyroid Stim. Hormone - 3.750 micro-Intl units/mL

(Reference Range: 0.465 micro-Intl units/mL - 4.680 micro-Intl units/mL)

Total T3 - 1.47 ng/mL (Reference Range: 0.97 ng/mL - 1.69 ng/mL)

I had these tests ordered by a health care provider that cares primarily for diabetic patients who has extra training in handling endo issues. (Endocrinologists are few and far between where I live). Just started seeing her. What other tests for a quick check-up of how a newly 'upped' dose would you suggest? And why. Thank you.

[SeasideSusie Remembering]

Total T3 is not a useful test.

To give a picture of thyroid status following increase in dose, you need TSH, Free T4 and Free T3.

What thyroid meds do you take?

Was the test done with the appropriate time gap after last dose?

When taking Levo last dose should be 24 hours before blood draw.

Last dose of NDT or T3 should be 8-12 hours before blood draw (adjusting timing of dose the day before if necessary).

[Smile4U in reply to SeasideSusie]

I called the practitioner just before I went for the blood draw to ask if I should wait to take my "Np Thyroid" till after the draw. She said no. So I guess the results are useless? I don't take any extra T3. When I have the next draw will definitely follow your suggestion. Ty. So, what do you think? I take 60mg of my Np Thyroid, up from half that 7 weeks ago. (Edit: Also, what reason should I give for asking for the Free T4 test? This practitioner doesn't seem to be very knowledgeable and want to gently lead her).

[Judithdalston in reply to Smile4U]

Curious to see a diabetic provider is doing your thyroid tests, is this in the U.K.? They unfortunately don’t seem to have been well trained for thyroid bloods if not asking for TSH, FT4 and FT3 then! Perhaps you could claim ignorance and ask what the difference between total and frees etc are, then thinking allowed say ‘oh then wouldn’t it make more sense if they tested free....?’

[SeasideSusie Remembering in reply to Smile4U]

Smile4U

Most doctors/practioners just don't understand that taking your replacement hormone means there will be a peak in hormone levels around 2-4 hours after ingesting so testing too soon will reflect the dose recently taken.

This is the advice always given here when having thyroid tests:

* Book the first appointment of the morning, or with private tests at home no later than 9am. This is because TSH is highest early morning and lowers throughout the day. If we are looking for a diagnosis of hypothyroidism, or looking for an increase in dose or to avoid a reduction then we need TSH to be as high as possible.

* Fast overnight - have your evening meal/supper as normal the night before but delay breakfast on the day of the test and drink water only until after the blood draw. Eating may lower TSH, caffeine containing drinks affect TSH.

* If taking thyroid hormone replacement, last dose of Levo should be 24 hours before blood draw, if taking NDT or T3 then last dose should be 8-12 hours before blood draw. Adjust timing the day before if necessary. This avoids measuring hormone levels at their peak after ingestion of hormone replacement. Take your thyroid meds after the blood draw. Taking your dose too close to the blood draw will give false high results, leaving any longer gap will give false low results.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 7 days before any blood test. This is because if Biotin is used in the testing procedure it will give false results (Medichecks definitely use Biotin, they have confirmed this and the amount of time to leave the supplement off).

These are patient to patient tips which we don't discuss with doctors or phlebotomists.

So if you took your NDT before the blood draw then your results will be showing a false high, how high depends on when you took it.

Taking NDT tends to lower, even suppress, TSH because of the T3 it contains, and it also tends to lower FT4. It's the FT3 that is important and tells us if we are overmedicated. It's not possible to interpret your FT4 (that is the Free Thyroxine test) without knowing when you took your last dose of NDT.

As for Total T3 v Free T3 - I realise you are in the US and this test is often used there rather than Free T3 test, however it is an outdated test. Most of the T3 in our bodies binds to protein. The T3 that doesn’t bind to protein is called Free T3 (FT3) which is the "active" part and that circulates unbound in our blood and is available for the cells to use. So the Total T3 test is measuring bound and unbound T3 whereas it's the amount of unbound T3 (free) that is more useful. We may have a good level of Total T3 but that doesn't mean that much is available for the cells to use.

[Smile4U in reply to SeasideSusie]

I took my Np Thyroid about 2 hrs before the blood draw. I got my first reply from my practitioner. She is agreeing to withholding my med before the blood draw. Next test in 6 weeks, and she's increasing my dose to 90mg.

[Smile4U in reply to Smile4U]

This practitioner also said that T3 was the same as FT3 for the tests. ?? Am I missing something here?