Thyroid UK
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Underactive thyroid

Hi I was told back in 1977 that I had an underactive thyroid gland, but Ive never ever have been been tested for T3 & T4 and yet a lot of people seem to get this test done, but not me when Ive asked about it Ive been told that I dont need that test, Im having blood test every six months and my thyroid count was dangerously low that they uped my dose of lethroxine up 300mcg I was on that dose for about 6yrs and now Im on 100mcg Im just so tired and all the diets they have had me on I still havent managed to lose any weight Im so fed up

11 Replies

Sorry to hear you're so unwell. Do you get copies of your blood test results? That's a good place to start.

It is odd that you were on 300mcg levo for six years and then that was reduced to 100. That is an enormous difference. It wouldn't surprise me if you were undertreated, but you need your results to know what's going on.


No Im never given any paper work with my blood scores on it I dont know anything and when I ask questions I never get any answers at all thanks


They will not offer them to you, you have to ask for them. You are entitled to access to your results, just ask for a copy. It's the only way to understand what has been happening to you.


Go for private testing e.g. Blue Horizon thyroid 11

1 like

Thank you for your help I will certainly get that sorted thanks


Your welcome,post the results when you get them with the ranges for the knowledgeable folk on this site to comment.


Ok will do thank you


Doctors are the least knowledgeable to know anything about hypothyroidism.

The first is that weight gain is a clinical symptom and we have to be on an optimum dose before dieting as dieting just wont work otherwise. It will just make the patient feel worse.

To have a dose of 300mcg and then drastically reduced to 100 is puzzling.

So now you have to ask questions, take advice from members who've also gone through the mill with adjusting doses upi/down/up down ie. treating blood test results rather than treating and relieving the patients' clinical sympitoms.

First things first. You need a new blood test. It should be fasting (you can drink water) and allow a 24 hour gap approx between your last dose of levothyroxine and the test and take it afterwards.

Always take levo first thing with a full glass of water and wait about an hour before eating. .Food interferes with the uptake. Any other supplements etc can be taken well apart from levo.

Ask GP to test, TSH, T3, T4, Free T4, Free T3 and thyroid antibodies. B12, Vit D, iron, ferritin and folate.

The lab may not do all of these thyroid tests and he may not request them. You can have a full thyroid blood test done privately by one of the recommended labs or the ones that the NHS lab will not do.

Always get a print-out from the surgery complete with ranges and post for comments. We are entitled by law to have copies and some surgeries charge a nominal sum for paper/ink.


Hi I am on Folic Acid 400mcg tablets, as my vitamin B12 was low as well as my Folic Acid since Ive been on the Folic Acid tablets my vitamin B12 has come back


When your B12 was low did your GP check the intrinsic factor to make sure you didn't have pernicious anaemia as I believe (and not medically qualified) that folic acid can mask a deficiency of P.A. Maybe ask the Pernicious Forum for confirmation.


Thank you for your reply, I have asked for other test to be done but they wont budge and do any other test, sometimes it feels like they cant be bothered about me


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