Elevated FT4 and TSH

[Janice46]

I’m on 100 Levothyroxine. My FT 4 andTSH are both elevated. Any ideas what the problem might be?

[SeasideSusie Remembering]

Janice46

It would help us to help you if you give us some more information please:

How long have you been diagnosed and prescribed Levo?

Current test results with reference ranges, eg TSH: 2.5 (0.2-4.2).

When did you take your last dose of Levo before the test?

Do you have any other results besides TSH and FT4 eg

FT3

Thyroid antibodies (need to know if you have Hashimoto's - autoimmune thyroid disease)

Vit D

B12

Folate

Ferritin

[Janice46 in reply to SeasideSusie]

I was first diagnosed with hypothyroidism in Oct 14 and settled down on 100mg a outa year later with a TSH varying around 2. My FT4 in Jan 19 was 20.5, Jan 20 was 21.6 and this month 24.4. MyTSH levels for those 3 dates were 6.11, 5.63, 4.58. I always take my Levothyroxine first thing in the am and my blood tests are also am - about 10am . I had F3 measured this time only - 4.2.Thsnk you

[SeasideSusie Remembering in reply to Janice46]

Janice46

You haven't given any reference ranges so we don't know if your FT4 is within range or not.

A high TSH with a high FT4 is abnormal. What has your GP said about these results?

Do you take a B Complex containing Biotin, or a Biotin supplement? If so did you take this in the 7 days before your test?

[Janice46 in reply to SeasideSusie]

Sorry - ref range FT4 12.3-20:2, TSH 0.3- 3.94 . Do not take Biotin. GP is emailing consultant - suggested problem with thyroid hormone receptor or pituitary gland problem.

[SeasideSusie Remembering in reply to Janice46]

I holpe the consultant is a thyroid specialist. Most endos are diabetes specialists and probably wont know how to interpret your results.

[liekki in reply to Janice46]

Based on those results I think you need a special kind of TSH test to see how reliable your results are.

There is a thing called heterophile antibody interference that can mess with your results. I have that one so my Tsh tests are called Tsh-abr, I hope I recalled that right. It's a test that blocks the confounding antibodies.

And that's not the only confounding factor that there is. Your doctor or lab should know about these things.

[Janice46 in reply to liekki]

Thanks - did you always have this antibody interference or did it develop? My figs have only changed this year

[liekki in reply to Janice46]

It's a thing that around 40 percent of populations possess, but it's a minority that have enough of heterophile antibodies to mess up certain labs. I seem to recall that it may vary over time how much of an effect they have.

My old labs are useless as a reference in any case because of this. Most of them seemed ok at the time, but since there were odd results sprinkled in an endo spotted this problem.

They are called heterophile antibodies because they are sort of generalized antibodies. They can elevated due to exposure to certain animals I think and mononucleosis at least.

There are other similar things also, human anti-mouse antibody is the only one I can recall right now.

It's a thing to consider at least.

[Janice46 in reply to liekki]

Thanks

[SlowDragon Administrator in reply to Janice46]

You should NEVER take levothyroxine before blood test

All thyroid testing should be done as early as possible in morning before eating or drinking any thing apart from water and last dose levothyroxine 24 hours prior to blood test

[liekki in reply to SlowDragon]

Hear hear.

Don't phlebotomists ask about levothyroxine routinely? Because they certainly do in Finland. Every. Time.

I tend to proclaim already at the door that no, I haven't taken my hormones this morning...

[Janice46 in reply to SlowDragon]

No one has ever mentioned that - but if the blood test is taken under same conditions every time, I don’t see the problem

[SlowDragon Administrator in reply to Janice46]

Your high TSH shows you need a dose increase in levothyroxine

If GP is not giving dose increase because of a falsely high Ft4 that’s clearly a problem

You likely have low vitamin levels too, when TSH is too high

Low vitamin levels result in poor conversion of Ft4 to Ft3. Poor conversion causes high Ft4 and low Ft3

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also EXTREMELY important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially if you have autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies

thyroiduk.org.uk/tuk/testin...

For thyroid including antibodies and vitamins

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random

If you can get GP to test vitamins and antibodies then cheapest option for just TSH, FT4 and FT3 £29 (via NHS private service )

monitormyhealth.org.uk/thyr...

NHS England Liothyronine guidelines July 2019 clearly state on page 13 that TSH should be between 0.4-1.5 when treated with just Levothyroxine

Note that it says test should be in morning BEFORE taking Levo thyroxine

Also to test vitamin D, folate, B12 and ferritin

sps.nhs.uk/wp-content/uploa...

Aim is to bring a TSH under 2.5

gp-update.co.uk/SM4/Mutable...

Official NHS guidelines saying TSH should be between 0.2 and 2.0 when on Levothyroxine

(Many of us need TSH nearer 0.2 than 2.0 to feel well)

See box

Thyroxine replacement in primary hypothyroidism

pathology.leedsth.nhs.uk/pa...

[SlowDragon Administrator in reply to Janice46]

So your high FT4 is a false high result

You need 25mcg dose increase in levothyroxine if TSH is over 2

Blood retested 6-8 weeks after each dose increase