Thyroid UK
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Low heart rate

I am on 150mcg of thyroxine I was on 100mcg but managed to get my dose up thanks to info I received on here.But whilst my TSH has dropped to 0.01 my ft4 is still only 14.6 (10.0-22.0) my ft3 was 4.6 I have just changed doctors as I have moved I said I felt a little breathless so he has reduced my dose to 125 mcg but I'm slightly worried as my resting heart rate was only 47bpm when on 150mcg just worried about lowering dose when even further my TSH is below range I know but everything else still points to being hypo if I understand correctly.Doctor was very dismissive he didn't do any kind of examination just listened do I decrease or go back and ask to stay on 150mcg hope this makes sense.

4 Replies

How is your B12? Low B12 (or iron) causes breathlessness.

1 like

I think it's important that your very low pulse rate is taken into consideration by your GP. Yours, at 47bpm is very low unless you are an athlete who sometimes have very low pulse. It's not always a good idea to lower your thyroid hormones unless it is too much (of which you will have the symptoms of overdose) but he obviously took your TSH into account too.

A low pulse is indicative of hypothyroidism as heart cannot pump efficiently if not on sufficient medication.


I'm definitely not an athlete it was when I was having an gym induction the man recommended that I saw a doctor as he thought my pulse was too low.The only exercise I do now is walking.Very frustrated with it all.Thank you for the reply


If there is another doctor you can see, I would make an appointment with him/her.


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