Blood tests: Hi. I just wanted you ask you lovely... - Thyroid UK

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Blood tests

McPammy
McPammy

Hi. I just wanted you ask you lovely people about when to or not to take your thyroid meds before blood tests.

I have quite a number of blood tests due in the morning. I have 9am cortisol amongst many others relating to thyroid.

I’m sure I’ve read that you should not tsken your meds before hand for at least 12 hours. However, my issues always happen after I’ve taken my NDT. I can collapse or maybe my legs go all wobbly too. Drs don’t know what’s causing this. I think it’s something to do with my meds. So if I leave them out I’m concerned it won’t be captured. Or should I ignore this and still abstain until after the blood tests

Many thanks

Pam

11 Replies

Well thyroid hormones don’t do anything until they’re in your cells, so the blood tests are a bit irrelevant. I’d follow the guidelines of not taking any in the 12 hours before the test, as you can do this for every test so you are always measuring the same thing and compare. Taking them before a test is highly likely to lead to a false high result and a dose reduction which may make you feel worse. It may be that you need to redistribute your dose or reduce it / or raise it?

I wonder if your blood sugar drops once your body experiences an increase in thyroid hormone following a dose? This sometimes happens if you’ve been undertreated for a while.

McPammy
McPammy in reply to Aurealis

Thanks for the advise. I’ll do it without meds then. Something happens when I take my thyroid meds. About an hour after I get lots a tingling and rushing. Sometimes it’s so bad my legs won’t hold me up. I’m not sure what’s happening. It’s like my cortisol is raging then suddenly burns out and my strength goes.

Just have no idea what it is. Sometimes instead of tingling and drop out I get a very heavy feeling in my chest almost like the brakes in my body have been slammed on and again my strength drops out suddenly. This will then last all day. And I can’t do a thing except lay down. I wanted to see if blood tests can pick any of this up.

Thanks again. Hope you are alright and level.

Pam

How long after taking your NDT do you get these symptoms?

McPammy
McPammy in reply to greygoose

Within the hour....

Aurealis
Aurealis in reply to McPammy

Is NDT the first thyroid hormone you’ve taken?

And what dose are you taking?

And do you have any previous test results?

McPammy
McPammy in reply to Aurealis

Hi. No I was on Levothyroxine for 11 years. This year something happened. I don’t know what. Then each time I took Levothyroxine within 90 mins I couldn’t walk properly. I was ok as I woke up then after taking it I could hardly walk, crawling sometimes. I reluctantly, as I knew I need thyroid med, stopped Levothyroxine. Within 36 hrs I was fine snd back to my normal strength. After a week I went to see my GP she was convinced also it was Levothyroxine. I got some NDT privately. I had no instructions from private Endocrinologist on how to start. I just took a tablet the next morning. That wasn’t good either. By now my TSH was 29. But I actually felt better! I persisted with NDT by lowering the dose at first and building up. I only need 1 grain of 60mg daily. Then I started to get better with it. I still have issues and can feel my body losing strength. It feels like something has put the brakes on inside me if that makes any sense. When normally I’m quite active and have no issues before this year. A few weeks ago I had a bad episode I couldn’t get off the floor. I ended up in A&E. My bloods ok except T3 slightly over the range at 6.1 late afternoon. I’m guessing it would have been higher in the morning when I was really bad. It seems that if my thyroid is out by a tiny bit up or low my body reacts and stops me from being able to move and strength loss. When this first happened in May my TSH was 0.22 low. My cortisol low 68. And ACTH low hardly detected 0.5 (2-11). Synacthen test said borderline Addison’s. The Endocrinologist said I had no Endocrine issue and sent me down the cardiac ward. Nothing wrong. Then down neuro route. Nothing wrong either. I’m still having Endocrine issues. I’ve sacked my Endocrinologist. He only saw me once and said he’d drawn a blank. Brilliant I thought, not!

Pam

Aurealis
Aurealis in reply to McPammy

How strange? If anything it sounds like sensitivity to thyroid hormone, which diminishes with optimal treatment.

Are you taking your NDT all in one dose, if so you may eliminate the symptoms by dividing into split doses - 2 or 3.

McPammy
McPammy in reply to Aurealis

Maybe split into 2. I’ll speak to new Endo which I’m seeing in 2 weeks. Thank you so very much xx

greygoose
greygoose in reply to McPammy

OK, so, why don't you try taking it when you arrive at the surgery, or wherever you have your blood taken, and then the person taking the blood will see first hand what it does to you. And they can still take the blood, because the pill/s won't have had time to get into your blood.

McPammy
McPammy in reply to greygoose

I do understand why not to take meds before hand. Just that my case is trying to understand what’s going on when the meds hit my system. It goes crazy fizzing or the opposite and crushes me down. Both ways I end up with no strength and can’t walk. It’s weird and never happened in all my 11 years prior on thyroid med until this year.

Thanks for you valuable help and support grey goose. There have been lots of them flying in magnificent unison over my home lately 👍😀

Pamela👍

greygoose
greygoose in reply to McPammy

Ah, that's a magnificent sight! Hope you manage to get some answers, soon. :)

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