Low TSH : So I've been on Carbimazole for around... - Thyroid UK

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Low TSH

ed2w profile image
ed2w
26 Replies

So I've been on Carbimazole for around 2 months now and thankfully I have seen some improvements symptom wise, still a long way to go. When I started my levels were:

T4: 36 pmol/L (12-22)

TSH: 0.001 (0.27-4.29)

Now at two months they are

T4: 20.2 pmol/L

TSH: 0.02

Does anyone know what this means? Does the TSH begin to rise later once the T4 has been normalised for a while. Would the low TSH still be the cause of some symptoms? I have had all the antibodies tests that everyone suggest and there is nothing to suggest anything autoimmune. Waiting on latest t3 results.

Thanks again

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ed2w
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26 Replies
Jazzw profile image
Jazzw

TSH doesn’t in itself cause anything - well, except to stimulate the thyroid to produce thyroid hormone when it senses a lack. But your thyroid was working overtime so the pituitary gland didn’t need to produce any TSH thyroid stimulating hormone). That’s why it was so low - and is still low, because your thyroid is still making sufficient thyroid hormones so far as it can tell.

I suspect you have Graves Disease - were you tested for it? It’s quite common with Graves for the TSH to never come back up to where one might expect, so you have to go by the FT4 and preferably the FT3 results to see the effect of carbimazole.

If you’re still experiencing hyper symptoms you might need a touch more carbimazole. But it’s best to wait for the T3 results to know for sure—it’s all too easy to end up on too much carbimazole and end up suffering under active symptoms instead, which when you’ve been used to “running hot” can feel doubly unpleasant.

ed2w profile image
ed2w in reply to Jazzw

Thanks, yeah been told it's not graves multiple times.

Jazzw profile image
Jazzw in reply to ed2w

Well, if it’s not Graves it’ll most likely be Hashimoto’s, which will eventually turn into you having an under active thyroid. Annoyingly, Hashimoto’s antibodies don’t always show up in blood tests.

Hope everything all settles down soon for you.

HIFL profile image
HIFL

Just checking, you've had TSI, TRab (TSH Receptor antibodies), or TBII run? Those are the Graves' antibodies, and sadly, many doctors don't know that and run the ones for Hashi's.

ed2w profile image
ed2w in reply to HIFL

it was a few months back now. I basically had a whole bunch of tests done, I can't remember the names of them but someone gave me a list on here and I brought it to them and he said that they were done and all came back negative. Been told its not hashimotos or graves.

Jazzw profile image
Jazzw in reply to ed2w

Then the only other possibility is some kind of hormone producing tumour which really ought to be investigated fully via a CT scan or MRI...

However, I think it’s more likely your doctor doesn’t know very much about how autoimmune thyroid disorders work and that it actually is either Graves or Hashi’s. Depressingly common, I’m afraid - that doctors just don’t know this stuff. You only have to read a handful of posts here to see how true that is...

ed2w profile image
ed2w in reply to Jazzw

well I've seen two endos who agree but I take your point. Ive been taking the carbimazole and its been working quite well in terms of levels and symptoms. Im guessing thats a good thing?

Cat4health profile image
Cat4health in reply to Jazzw

It can be a transient thyrotoxicosis which can be related to other things than a tumor. It has been known to happen because of pregnancy, the pill and eating too much iodine.

greygoose profile image
greygoose in reply to ed2w

One negative blood test does not prove you don't have Hashi's for several reasons. 1) Hashi's antibodies fluctuate. 2) There are two Hashi's antibodies, did they test for both of them - TPO and Tg ab. 3) Some people have Hashi's without ever developing high antibodies. So, testing TPO can prove that you do have it, but can't prove that you don't.

ed2w profile image
ed2w in reply to greygoose

but I thought hyperthyroid was linked to graves and hashis was more linked to hypo?

greygoose profile image
greygoose in reply to ed2w

Grave's is hyperthyroid, yes. But with Hashi's you can have both hypo and hyper blood test results and symptoms. Especially in the early stages. And doctors are so ignorant that they often confuse the two. Which is why I always check with people.

Your Grave's antibodies are negative, so you don't have Grave's. But, with Hashi's, a negative result doesn't prove you don't have it because Hashi's antibodies fluctuate.

There is no treatment for Hashi's, anyway. All we can do is take thyroid hormone replacement during the hypo phases But, gradually, the thyroid will be destroyed so that we are always hypo, with no 'hyper' phases. Hashi's may go into phases of remission, like Grave's, but unlike Grave's, it always comes back.

And the problem is that when doctors who don't know the difference between Hashi's and Grave's, see a suppressed TSH, they always reach for the carbimazole. But, that's the wrong treatment for Hashi's, because it rapidly sends the patient hypo. Then, as the doctor doesn't understand much about how it all works, he insists that the increasingly hypo patient stay on carbi, to the detriment of the patient.

Hope that's clearer. I know it's complicated. :)

ed2w profile image
ed2w in reply to greygoose

Well I had high T4,T3 and ow TSH consistently before I started treatment. And since taking Carbimazole I have noticed great improvements. There hasn't been anything to suggest I'm anywhere near going hypo yet.

greygoose profile image
greygoose in reply to ed2w

Not yet, no. And the Carbi has reduced your Free levels, so that would make you feel better. But, the point is, you need to know what is causing them, and your doctors don't seem to have the first idea.

ed2w profile image
ed2w in reply to greygoose

well if you can't prove you do have it what do you, you can't treat something your not sure you have?

Marz profile image
Marz in reply to ed2w

You were told your anti-bodies were negative - but did you obtain actual copies of the results for your own records. Results are legally yours and we have seen mistakes here on the forum before ..

ed2w profile image
ed2w in reply to Marz

Yeah i saw them a few months back before I started treatment.

ed2w profile image
ed2w in reply to ed2w

Someone brought this up before. The doctor told me I the results were negative, I Was sent a letter that said they were negative. Why would the doctor lie to me about that? Would that not be illegal? If they were lying to me then why has the carbimazole been so effective?

greygoose profile image
greygoose in reply to ed2w

No-one is saying that your doctor is lying. What we're saying is that your doctor is ignorant and doesn't understand how to read lab test results - believe me, it happens all the time! They just cannot understand the results.

The carbi has been effective because it has lowered your FT4/3 quite a bit. Too much thyroid hormone will make you feel bad, so lowering it by any means will make you feel better. But, as I said above, that is not the point. You need to know why you have high levels. If it's not Grave's, and it's not Hashi's (although that result looks positive to me), then what is it? They should not just sit back and say, 'well, the carbi's working so that's ok', they should be pressing to find what caused it in the first place. Have you at least had an ultrasound on your thyroid?

Marz profile image
Marz in reply to ed2w

Yes you were told your anti-bodies were negative - but which ones ?

Valarian profile image
Valarian in reply to ed2w

I think the point is, if endos say you aren’t hyper due to Graves’ or a hyper phase of Hashi’s, it would be worth asking what they DO think has caused it.

These links mention some other potential causes of being hyper:

thyroiduk.org.uk/tuk/about_...

btf-thyroid.org/information...

SlowDragon profile image
SlowDragonAdministrator

You are legally entitled to printed copies of your blood test results and ranges.

UK GP practices are supposed to offer online access for blood test results. Ring and ask if this is available and apply to do so if possible, if it is you may need "enhanced access" to see blood results.

In reality many GP surgeries do not have blood test results online yet

Alternatively ring receptionist and request printed copies of results. Allow couple of days and then go and pick up. They can no longer charge for printing out, rules changed after May 25th 2018

Important to test vitamin D, folate, ferritin and B12

As well as all relevant antibodies

Far too often they don't test antibodies for Graves, just assume it is

Link about antibodies

thyroiduk.org.uk/tuk/about_...

Valarian profile image
Valarian

TSH is a hormone produced by the pituitary gland to tell the thyroid to produce more hormone. If you have an excess of thyroid hormone, TSH will be low. It also tends to remain low for a while in people who are being treated for Graves’, but it looks as though you don’t have this.

Your TSH is still quite low, but your thyroid hormones are still towards the top of the range.

Other causes of a hyperactive thyroid include:

Thyroiditis

btf-thyroid.org/information...

Toxic multi-nodular goitre or adenoma:

btf-thyroid.org/information...

Some general info:

thyroiduk.org.uk/tuk/about_...

btf-thyroid.org/information...

Rmichelle profile image
Rmichelle

I think you need to obtain copies of your bloods for your own keeping and see where you feel good at, it is best always to get copies and never take it from your gp that they are normal or ok! I have had a couple of gps who do not understand thyroid bloods and one even telephoned me to come into surgery and see the results has he did not know anything about them!! Please do not take it the wrong way but everyone here just wants to make sure you are getting the best advice.😊

ed2w profile image
ed2w in reply to Rmichelle

Im getting my most recent tests sent out to me. Will update this when I get them.

diogenes profile image
diogenesRemembering

With hyper symptoms you'll need to measure TRAB antibodies (thyroid receptor). Which ones have been measured?

ed2w profile image
ed2w in reply to diogenes

I can't keep up with all this stuff, sorry I didn't reply. Here is my last correspondence with my endo.

"The reason I was not prepared to diagnose Graves’ disease as the cause of your hyperthyroidism just yet was that your thyroid autoantibodies are all negative. In other words there is no confirmation of underlying thyroid autoimmunity. Specifically the TSH receptor antibodies were not positive. These are the typical Graves’ disease antibodies."

Here is a test I did with medichecks:

THYROGLOBULIN ANTIBODY <10 IU/mL 0.00 - 115.00

THYROID PEROXIDASE ANTIBODIES 10.4 IU/mL 0.00 - 34.00

What else do I need to ask about.

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