Stupid question but still asking...!

[Tracer]

I have Hashimoto's (proved by antibodies test) ie primary hypothyroidism and my first TFT levels (in 2009) were:

TSH 12.74 [0.35-4.5] FT4 15.1 [11-26] FT3 5.0 [3.9-6.8] - 6 mths later (still no meds)

TSH 15.12 FT4 14.7 FT3 4.5

A few weeks ago, having been off all thyroid meds (in my case, T3) for 66 hours (and hence feeliung extremely hypothyroid), my levels were:

TSH 0.03 [0.34-5.6] FT4 1.5 [7.9-20] FT3 2.5 [3.8-6.0]

(Interesting how much the RRs have changed..!!)

If I had these latest levels in 2009, it would have been seen as a pituitary faliure ie secondary hypothyroidism.

My question is - can you have primary and seconday hypothyroidism..?!

Thanks

[humanbean]

Your blood test levels are consistent with someone who takes T3 only, and who had had several days without medication.

The body reduces the amount of TSH it produces when the hypothalamus detects good levels of T3. If the amount of T3 is reduced, TSH doesn't recover lightning fast so there will be a delay before the TSH will rise to realistic levels.

Your body only produces T4 when it knows you need to have some for conversion to T3. Since you are taking T3 there is little need for T4, so your level is low.

And your T3 was low because you hadn't taken any for 66 hours, and your body hadn't yet geared itself up to produce what it could from your thyroid or other body tissues.

You may have secondary hypothyroidism for all I know. But you can't diagnose it on the basis of your current tests under the circumstances you have described. Hope this helps.

[Tracer in reply to humanbean]

Thank you, Humanbean, yes, very helpful.

I assumed 66 hours wasn't long enough to get true levels and so what you say makes perfect sense.

[humanbean in reply to Tracer]

How long do you intend to go without medication? And why are you trying to get "true levels" anyway? You could be suffering for months, and I'm not sure what you hope to gain from it.

Bear in mind that treating someone with thyroid hormones when they don't have hypothyroidism will make them feel very ill. The fact you were able to take thyroid hormone suggests that you do have thyroid disease.

-----------------------------------

I've just re-read your original post. If your pituitary can produce high levels of TSH, as it clearly did in two different tests in 2009, then you don't have either secondary or tertiary hypothyroidism. The fact that, in the second test, your TSH rose and your FT4 and FT3 dropped says to me that your thyroid was already well on the road to failing in 2009.

Because you have shown positive antibodies your thyroid hormone levels may fluctuate a lot until your thyroid has been destroyed enough to make you permanently hypothyroid. Whether you have reached that level yet is going to be difficult to say since you've been taking thyroid meds. Thyroid destruction by thyroid antibodies can take decades.

Is your doctor trying to stop you taking medication?

[Tracer in reply to humanbean]

Hi Humanbean,

Yes, I am 'truly' hypothyroid and have been on meds since 2010 (T4, then T4 + T3, then Armour, now T3 only). No, my Dr isn't trying to stop me taking meds - although he's almost as clueless about it all as most GPs but is really good and prescribes T3 for me as he appreciates that I clearly don't get sufficient active T3 into my cells when on T4 (or Armour) - as I don't convert/RT3/cortisol problems preventing cell entry, etc.

I am currently under Dr P for adrenal help - I did a salivary profile in 2011 and 2015 and it was bad and is now worse - so, in line with Dr P's instructions, I had to come off T3 for 7 days. I couldn't get a TFT done later than after three days, but thought I'd still do one, just to get a feel for how the levels might be looking after that length of time (I'm now back on T3 - and taking NAX). But, as you pointed out, they don't tell me much.

(I'm very glad to be back on the T3 and felt truly horrendous off it!)

[Clutter]

Tracer, I don't think one can have primary and secondary hypothyroidism. Primary is caused by thyroid failure to produce sufficient hormone despite high TSH.. Secondary is caused by lack of pituitary stimulation (TSH) to a healthy thyroid gland.

[helvella Administrator Thyroid UK]

Unlike Clutter, I am convinced that some combinations of primary and secondary (or even tertiary) hypothyroidism are possible.

Of course, if your primary hypothyroidism is such that your thyroid can't make any thyroid hormone, it doesn't make much difference whether or not your TSH is appropriate. But I suspect that some people have mild primary hypothyroidism, but their TSH doesn't rise sufficiently to either push the thyroid into making a bit more, or reveal hypothyroidism in a TSH test. They could continue to suffer for many years.

[Tracer]

Thanks for responding, Clutter and Helvella.

I assumed you couldn't have both but wasn't sure and hence the question; an interesting thought if your body could be pushed and pulled by different causes - and a nightmare getting a GP/endo to react to them all when they have such a difficulty with just one..!

I think humanbean was right in my scenario, 66 hours just wasn't long enough to get a true base-line picture, unfortunately; I would have been interested to know how my body gets on 'on it own'.