High FT3

[BlondeThistle]

Hi all, hoping you might be able to help me interpret my most recent thyroid test results. Had the tests done due to recurrent early miscarriage (3 over the last 6 months, I’m 29 & everything else looks good).

My results are:

TSH : 1.03 mIU/L, range 0.27-4.2

FREE T3: 11.2 pmol/L, range 3.1-6.8

FREE THYROXINE (T4): 19.8, range 12-22

THYROGLOBULIN ANTIBODIES: 14.5 kIU/L, range 0-115

THYROID PEROXIDASE ANTIBODIES: <9 kIU/L, range 0-34

Going by above, my T3 seems really high? There’s not much online about normal TSH & T4 levels but raised T3.

Does anyone have any insight? Does it look like hyperthyroidism? Going to phone GP in the morning to discuss.

[PurpleNails Administrator]

Welcome to forum

Sorry for your pregnancy losses.

Your results are quite unusual.

Do you have a diagnosed condition? Take any replacement? Or are you new to thyroid issues.

Often even slight elevations in FT3 tend to cause under range TSH. So your doctor will be confused because your TSH is healthy.

Your antibodies are negative. With over range FT3 ask to have a referral to endocrinology & they will test TRab or TSI antibodies also.

Do you have symptoms?

I had high FT3 & borderline FT4 but my TSH had became low first. This was from a nodule over producing, this can often cause disproportionately high FT3 and is also see with autoimmune hyper 10% of the time.

Do you have any swellings in thyroid area or either side of your neck. Look at the lower part of your neck just a little above collar bone. It can help If you have a bottle water and gulp water with your chin lifted up can go unnoticed unless looking.

What time was your test taken? Had you fasted the night before?

Do you take supplements? Biotin can occasionally affect results & falsely skew results.

[BlondeThistle in reply to PurpleNails]

Thank you for this! I did think the results seemed very odd.

I have no diagnosed conditions, have never had any issues medical-wise until this recurrent miscarriage situation.

As for symptoms, I could identify with the following: racing heart, insomnia on and off, excess sweating especially hands & feet and can get periods of night sweats too, a short luteal phase (excess t3 & t4 can cause this), frequent urination and I get really bad itchiness at times at night.

I haven’t lost any weight though and I know that’s a big symptoms so I wasn’t sure if all of the above is just a coincidence.

I’ve had a look and definitely don’t think my thyroid is enlarged in any way.

Test was taken at 10am and I did not fast the night before.

I do take supplements, just your standard fertility ones but none have biotin in them and I didn’t take for 3 days leading up to the test.

[PurpleNails Administrator in reply to BlondeThistle]

Symptoms can be varied & individual - I had some insomnia, sweating, itchiness too but nothing I thought was serious. I gained a lot of weight which I put down to severely strong appetite but no energy, but doctors do assume hyper causes weight loss. After being told my thyroid was ok I returned to the doctors because my finger nails starting detaching. That’s when it was noticed the right tests hadn’t been checked.

My heart rate was fast but I hadn’t noticed it. I now have a fitbit & find resting heart rate is correlated to thyroid levels fairly accurately.

I was diagnosed years after having children but these symptoms had developed very slowly over years & I now think of may have been an issue then, I had high blood pressure & my thyroid was never tested before or during pregnancy. It is better to know & resolve a thyroid issue before trying to conceive.

[BlondeThistle in reply to PurpleNails]

Your finger nails were detaching?! Mine are! We thought I had maybe suddenly developed an allergy or something to nail polish.

Thanks for explaining your story!

I spoke to the GP on the phone and he wasn’t very helpful if I’m honest. He said the FT3 being elevated doesn’t mean much? And he wasn’t keen to explore more. I’ve pushed for additional testing so getting the bloods done via NHS on Thursday

[FallingInReverse in reply to BlondeThistle]

Hi, I am so sorry for your pregnancy loss. My heart goes out to you, and I hope you can find some hope and healing here as you take control of your next steps.

For myself and many others, for years (for me it was 8+ years) we also had no "diagnosed" issues but also had a laundry list of seemingly unrelated "coincidences." For those 8 years there was nothing in any blood test that indicated anything was wrong and it took so long to get on a path to feeling better. If you do indeed turn out to have Thyroid issues, you are very lucky to have found this board so early in your journey.

And whereas many of us share symptoms - those symptoms are so broad that they could mean so many other health issues. Plus even though I am full on hypothyroid, I too have never had a weight problem, and never had a few others typically associated with hypothyroid. I'll also say when I was diagnosed, my doctor stood across the room and said "your thyroid is enlarged." To this day I still can't see it myself at all no matter what angle I look from and apparently I have a 2 cm diameter growth on it. We have a lot of commonalities, but not one of us is the same. Which makes it so confusing especially in the early days.

Symptoms are important - but it's the symptoms PLUS the right blood test (PLUS this board's wisdom and advice) that will get to an answer. Read the responses to your post here carefully, speak up for yourself with the doctor, and be bold in asking for the blood tests our admins recommend. It will save you tons of time. I wasted months getting blood tests that were not helpful because I trusted the doctors to know, and almost none of them do.

Good luck and keep us posted!

[Hedgeree in reply to BlondeThistle]

Hi BlondeThistle,

Do any of your supplements contain kelp or iodine?

[jimh111]

Your thyroid hormone levels are high but your TSH is not suppressed. This is beyond the capability of a GP so I would ask for a referral to an endocrinologist, especially in view of your miscarriages.

It could be a number of things.

These fT4 and fT3 assays could be giving false results due to assay interference an endocrinologist can request different assay types to rule this out.

It could be a rare genetic condition called resistance to thyroid hormone (RTH). In this case your endocrinologist would consult with, or refer you to, a specialist clinic for genetic tests. If you have RTH you would receive counselling, which is advice about your condition.

So, me view (and I’m not a doctor) is to request a referral to an endocrinologist as you have discordant results and a referral is consistent with NICE guidelines.

[BlondeThistle in reply to jimh111]

Thank you for replying! This is really interesting, I’ll definitely ask to get referred to an endocrinologist when I speak to the GP tomorrow. Hopefully it is as you say and the assay is giving false results.

[jimh111 in reply to BlondeThistle]

Yes do. Without going into very deep technical details RTH can present with a mixture of hypo and hyper symptoms as different receptors are affected to different extents. Try to make sure you get a referral as you don’t want a GP procrastinating, doing another blood test with the same lab will be a waste of time.

Assay interference is rare and usually occurs in people who work closely with small animals (the assays use antibodies from mice, rabbits etc.).

[HealthStarDust in reply to jimh111]

resistance to thyroid hormone (RTH)

Is there a test for this?

[jimh111 in reply to HealthStarDust]

RTH is caused by mutations to the TRB (B beta) receptor. It presents with elevated fT3 and fT4 and a non-suppressed TSH, patients may be clinically euthyroid or hypothyroid. Tests are carried out in the UK at Addenbrooke's but patients can only be referred by an endocrinologist not a GP.

This is a rare condition and other causes of unusual blood test results are ruled out first. I've never seen anyone on this forum who have had this, so it is rare. It is difficult to assess how many people are affected, the best guess they have so far is around 1 in 40,000 people.

[HealthStarDust in reply to jimh111]

Thank you for sharing that with me.

[BlondeThistle in reply to jimh111]

He was not keen to refer me at all. Said the elevated FT3 doesn’t really mean anything especially because my TSH and FT4 are in range.

I’ve pushed and getting them all tested again on Thursday with the NHS and he said he could then get a second opinion if they come back high.

Just a bit confused as you say assay interference is rare so I’d surely get similar results to the ones I posted above via nhs

[jimh111 in reply to BlondeThistle]

fT3 is important, it does mean something because it is inconsistent with your TSH. Where did you get your blood test done? It's possible the test went wrong. A second test will give mildly different results, especially if it uses a different assay. It's vital they teat fT3, the labs usually refuse to do this for a GP so the GP should state that it must be done.Try to get your results as soon as they are available, if they don't include fT3 submit a polite complaint to the hospital PALS.

[BlondeThistle in reply to jimh111]

I got it done with medichecks and the result was reviewed by one of their doctors who recommended further evaluation for the raised FT3. As far as I can see, medichecks seems to be pretty reliable? It was a venous blood draw performed by a nurse.

Ok will do thanks, he did say he’ll request FT3. I’ll say to the nurse who takes it that we need to make sure FT3 is included.

Thanks for your help!

[jimh111 in reply to BlondeThistle]

Your test should be reliable. Get the nurse to ensure a note is put on the form to say fT3 must be done. The labs invariably fail to do fT3 unless they are told quite bluntly to do it. It's very frustrating, I submitted a freedom of information request and it costs my local hospital 93p to check fT3 and they still mess us about.

[HealthStarDust]

I just wanted to share that I am sorry about your pregnancy losses.

Depending on when your last loss was, it may be an idea to repeat tests some months after as there’s all sorts going on with the thyroid as a result of all the other hormones involved. There’s not much written about this, but it was advise I received.

[BlondeThistle in reply to HealthStarDust]

Thank you! Last loss was end of August so hoping my thyroid hormones would have returned to normal but getting a repeat done on Thursday to check again

[HealthStarDust in reply to BlondeThistle]

I’d say it’s worth waiting a couple or so periods to pass before retesting (assuming you had a predictable cycle pre pregnancy loss). No science behind this suggestion, except personal experience that your period cycles are at least indicative in some way of letting you know that things are rebalancing.