Confusing Test Results

[DonegalGirl]

Hello, my teenage daughter has had 3 lots of blood tests.

In week 1 her TSH =4.82-Serum T4 -18.6

In week 3 her TSH=2.29-Serum T4-12.9

In week 4 her TSH=4.79-Serum T4-17.4

(Ref for TSH =0.51-4.30)

B12=486 (Ref 197-771)

The GP did not test T3

She has been on 200mg iron pills since week 2, following the first test but the Ferritin remains low, c.10 in all three tests.Ref (13-150)

Serum iron=7.5, in latest test.Ref-(5.8-34.5)

Anti TPO Ab (jeb) =15 Ref-(0-34)

No other antibody tests taken

She has been referred to an endocrinologist as the GP is concerned at the fluctuating TSH levels.

Can anyone tell me what this means please?

Is the thyroid problem (and her numerous symptoms eg-tingling, depression, weight gain,acne) caused by the low Ferritin level.

Also any advice on what to highlight with the Endo would be great.Thank you

[SeasideSusie Remembering]

We're all the tests done at the same time of day? Had she eaten before them or not?

TSH is highest early in the morning and lowers throughout the day, so if tests done weeks 1 and 4 were early morning and week 2's test done in the afternoon then that would account for the difference in levels. Eating also can lower TSH.

How long since she started iron tablets? It can take months for Ferritin to rise with tablets. Does she take each iron tablet with 1000mg Vit C to aid absorption?

[Greybeard]

There is a circadian rhythm to tsh, unless blood was draw at the same timeof day the differences may not be significant. Tsh is highest very early in the morning and naturally falls as the day goes on. It is unlikely gp will know this.

[greygoose]

It's not the fluctuation of her TSH that is concerning, but how high it is. Over 3 is not normal - although her doctor wouldn't know that, either. We really need a range for that T4, but it doesn't appear to be low. So, her FT3 is probably low. And that is what is likely to be causing her symptoms of depression and weight-gain. But the tingling could be the B12, although it's not excessively low, but should be at least over 500.