I’m interested in the correlation between these two, as have seen it mentioned a couple of times but don’t really know much about the link. All things thyroid are super new to me
Little bit of background- slightly elevated TSH picked up by fertility clinic following IVF and miscarriage. TSH was 3.1, so only mildly elevated.
They have put me on 50mg of Levo to try and get my TSH down to between 1 and 2 but preferably below 1.
We’re not allowed to start our next IVF cycle until its in range and I’m eagerly awaiting my first blood test to see if the Levo has done anything.
I do completely understand that I need to wait for the results and nothing can tell me what my TSH is without the blood test.
However I was keen to know if my resting heart rate would be an indicator as to whether the Levo is doing anything?
I am pretty fit and healthy but my resting heart rate for the last couple of years is in the high 30’s / low 40’s.
Should this increase as my TSH reduces or is it really not that simple?
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Bramble83
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I am sure some of the admins will give you their great advise.
With that low of a resting heart rate, one would expect it to rise with "optimal" treatment. However, the relationship is not to TSH but rather to free T3 levels. If they are only testing TSH, they may not get you well enough to have a successful IVF. (And shame on them not doing a full thyroid panel on you before your first IVF - my condolences on your loss.)
For example, my TSH was elevated, but my free T4 was low and free T3 level was at the very bottom of the range. Doctor gave me an initial dose of NDT. At next blood test, my TSH had come down into the normal range, but my free T4 and T3 were both LOWER than before I started medication. My doc said, GREAT...I am not going to increase your meds as all three are now in range. I said TERRIBLE...I feel worse than when I started (which makes sense because my fT3 was lower).
If they are only testing TSH, that is a concern. You may need to go out on your own to get the full profile.
Thanks for the reply- I didn’t realise it was the T3 that correlated to the heart rate, rather than the TSH.
They only tested my TSH and T4, but I also have Addison’s disease, so my form for the 6 week blood test is from my endocrinologist and he had put T3 as well, as he said we need that for the full picture.
I know i’m being impatient (!!!) and only the blood test will tell me, but I can’t help but wonder if my heart rate hasn’t moved up by so much as 2 bpm, whether the 50mg of Levo has had no effect yet 😞
I can understand the impatience. When hubby and I married, he had been diagnosed with hepatitis c (from blood transfusion as a small child) but had to have issues relating to his congenital heart defect addressed before he could treat the hep c. What should have been a simple procedure turned into a series of 7 surgeries over 18 months. Then the hep c treatment. All-in-all, we could not even discuss trying for 4 years. It was horrible waiting.
Go to thyroiduk.org and start reading. That will give you good background information. Then come back and start reading posts. The short story is that TSH is made by the pituitary to tell the thyroid how much hormone to make. It makes T4, T3, T2, and T1 in different amounts. Free T4 is a storage form that circulates in your system and is changed into T3. It is the active free T3 that the cells of the body need to function. Even having “enough” T4 doesn’t guarantee you have enough T3. Testing all (tsh, free T4 and t3) gives a clearer picture of where the issues might be.
If you have Addisons, your TSH (a pituitary hormone) may not accurately represent your thyroid hormone levels and your Addisons may affect your heart rate more than T3
Definitely primary- my ACTH was through the roof, so pituitary is definitely working, just my adrenals that won’t respond. I was positive for adrenal antibodies too.
You heart beat is very slow Bramble, bradycardia, not normal at all.The heart beat slows with hypothyroidism. Have you had hypothyroid symptoms for quite a while? Your heart beat should increase with treatment. Can I ask if they have taken your B12, vitamin D, folate and ferretin as well as these are needed for your body to use the thyroid hormones.It is possible for your TSh to be below 1 and for you still to be unwell if your vitamins are not up to speed. It might also be the case that you might not need IVF to conceive if your thyroid health is optimal which it clearly is not with that slow heart beat. Thyroid care is terrible in the Uk and it is quite possible for your doctors to have missed it all this time. I had fertility treatment, no IVF but I took clomid for both my boys. I find it alarming as I look back to realise that I went through two pregnancys with low iron, low Vitamin D and an untreated underactive thyroid inspite of having been seen by several doctors both private and NHS. I wish you well.
My heart rate has been low for at least the last couple of years (that’s how long i’ve noticed as my Apple Watch alerts me every morning saying below 40 isn’t normal 😂). I asked my endocrinologist and because I do quite a bit of running etc, he said it’s just because i’m fit and nothing to worry about!!
It’s super tricky to say about the symptoms, as I have Addison’s disease, so always put anything down to that, as main symptoms for that are fatigue, nausea and brain fog. Although i’m pretty well with mine and tend to only feel rubbish if my tablets are late (I do circadian dosing and take steroids every 4 hours)
Having done a bit of reading up, the ones that don’t seem to be very Addisons and maybe more thyroid are the heart rate one, hair loss and the fact i’m permanently freezing cold - I know my basal temp on waking as had to do it for all the fertility stuff and in the winter when it’s colder it’s generally around 35.8-35.9 and now it’s warmer it’s about 36.1-36.2.
I have noticed that my sleep seems to be improving (my Apple Watch monitors how much deep sleep I get each night) since about 3 weeks into the Levo. Might be coincidental but i’ve never managed more than about 1 hour- 1 hour 30 max for deep sleep and over the last week or so, it’s creeping up and is now at 2.5-3.5 hours, which it’s never done in the 2 years of my tracking it!
I did a medichecks last year when my hair was coming out on handfuls and these were the results for the ones you mention;
Ferritin 48 (13-150)
Folate 19.8 (3.89-26.8)
Vitamin D 68 (50-175)
B12 248 (38-188)
At the time i’d been supplementing with a high strength B12 and folic acid, as recommended for fertility. I have since stopped these.
I saw a specialist for my hair loss and she told me my ferritin needed to be above 70 so I began supplementing with iron back then and had another test done by the GP and it was up to 70 (sorry they didn’t give me the range)
I was going to wait another couple of weeks until i’d done 6 weeks on the Levo and get the whole lot done again.
Would love to think we might not need the IVF if I get my thyroid levels right, but unfortunately I have premature ovarian failure to add to the list of autoimmune diseases, so think that might be a bit optimistic. But you never know 😀
When we first started the actual IVF about 6 months ago my TSH was exactly 2.5 (they didn’t tell me at the time), which they’ve now said is at their cut off- would have been good to know them.
I’m really hoping the fact my heart rate hasn’t moved a beat upwards, doesn’t mean the 50mg of Levo has done nothing!!!! 🤞🤞🤞 But have a horrible feeling that might be the case.
Olympic athletes might have a pulse of 50/55 but no way is one dropping into the 30s or 40s normal even if you do run a bit. It does sounds like you are hypothyroid. I would imagine the T4 will have dropped your TSH and the fertility doctors will want to go ahead with IVF, the problem is that it probably hasn't done much else but alter a blood result. You will be no healthier. Your ferretin needs to be around 90 for thyroid hormones to work properly and you need to supplement your Vitamin D with some vitamin D and K2. Can I suggest that you see a endo from the list of more helpful endos available via our website. Having a child is very very taxing both mentally and physically. I would also say that it is unsafe to have a child in the Uk if your are prone to mental health issues due to the possibility of them being removed. Low thyroid hormones can easily lead to depression. I will look up ovarian failure.
I’m not sure whether I can see separate endos for my Addisons and thyroid? My endo is brilliant for my Addisons, which is clearly quite dangerous, so I don’t want to do anything that would change my relationship with him, as he lets me lead all of my own care, dosage etc and so many people with Addison’s really struggle with ignorant endos.
I will definitely check my ferritin again and make sure it’s above 90 and will get a vitamin D supplement as recommended.
I appreciate what you’re saying about having a child and it being difficult and I guess I won’t have any idea until one comes along. Luckily I don’t have any mental health issues but will definitely keep an eye out for that.
Gosh how difficault. I am aware that most endos are only really any good with diabetes. Keep us updated here and maybe we can help you work alongside endo you have. We have lots of information, regular posts of studies just published etc that you can take to show him. It sounds like a good idea to focus of vits and minerals.
High 30s low 40s as in beats per minute? That’s like hibernating. Perhaps you’re expressing in some other term. Beats per 30 seconds? Yes, the hormone replacement would be expected to increase your metabolism, and you would see some change in heart rate.
My resting pulse would fall to 47 (when reclining) in the early morning hours. This rate makes a finger pulse oximeter flash in distress/warning. I’m at least 10 bpm higher with treatment.
If i’m sat at my desk in the day, it’s generally around 46-48bpm but overnight it is always below 40bpm, generally around 37-38bpm.
My Apple Watch doesn’t like it either and sends me a red warning alert every morning.
My endocrinologist isn’t worried but I had read there was a link between that an led thyroid and was interested.
I must also have the slowest metabolism in the world, as I hardly eat anything (no more than 1200 calories a day), do lots of exercise (run 3-4 times a week plus cycling plus tennis) and it’s impossible for me to lose even 1lb of weight.
What did your heart rate increase to, once your thyroid was at the right level out of interest?
I’m still working on it because it appears my thyroid has completely gone ‘round the bend, driven off a cliff into the sea. Genetically I’m not a good candidate for levothyroxine. I’m fiddling with T3 doses at eight-hour intervals, whilst running half-life computations in an Excel spreadsheet.
It’s easy to move the metabolism with T3. (The levothyroxine did elevate my heart rate as well, but after several weeks I was getting worse; after months I could hardly function)
I’m reading 72 bpm right now, at seven hours post dose.
Wow, it sounds like you’re having to put in a lot of time and effort to get yourself well- I really hope it works out for you.
When I had my original thyroid checks done, my TSH was fine and so was my T4 but my T3 was at the bottom of the range, so i’ll be interested to see what the T3 is now that maybe TSH has increased.
50 Levo is a low starting dose. It’s going to take time to have any effect and may we’ll need a dose increase. The fact that you feel cold all the time is a sign you are hypothyroid.
Thank you, will have a look. I am totally guessing here but I manage to do a lot of high intensity cardio exercise, which i’m guessing I would really struggle with, if my oxygen saturation was low?
I have SCH and when diagnosed had very slow heartbeat (40) and low body temperature (34.5). Over the past year on meds t4 then mix t4 and t3 my heartbeat is normalising and I’m a degree warmer. So yes definite correlation.
Hi Branble83. My resting heart rate (measured 24h by Fitbit) averages c.56bpm. I’ve been on Levo then also on added liothyronine for over 2 years and at different doses and the different hormone blood levels there has been no noticeable change in my heart rate. It naturally fluctuated but there does not seem to be any relationship to the hormone levels in my blood.
It will be doing something already but the dose may not be enough to bring the tsh low enough yet. My tsh was initially c.5.6 but it didn’t get down to c.1 until I was on 100mcg I think. Then another 50mcg reduced it to c. 0.2. However the ft3 is the most important marker as tsh will react to ft4 levels alone or it may drop disproportionately low to the hormone levels. Personally I could never work out how to predict ft4 and ft3 from the tsh level. Some people posting on here had similar ft4 and ft3 to mine at times but their tsh was always far higher than mine. I felt very ill for many years despite all readings being within their ranges so the blood results don’t always translate to the state of health, sadly.
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