Very new to this as have only received Hashimoto’s diagnosis in the last few weeks. I have been on a 75mg Teva for 2 weeks and have noticed my resting heart rate increase by about 20bpm since I started medication (recorded day and night on smart watch).
I’m very active and run a lot so my resting heart rate is quite low anyway, but the increase in heart rate at night (although only 20bpm) is affecting my quality of sleep.
Is it normal to see this increase? Dr does not seem to think medication in causing this but it’s very clear on my hr data that this is only since being medicated.
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Runnergirl2023
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Welcome to the group. If you could fill in your profile it helps members to understand your thyroid journey when responding to your posts.
So did you start straight away on 75mcgs Levothyroxine or have you built up to that over a some months? Usually starting dose is 50mcgs but can be higher in someone who's fit. Higher starting doses don't always agree with people though. The body has been trying to cope for probably a long time and it can be a shock to the system to suddenly introduce what it has been needing, causing symptoms. Some people are more sensitive to hormone changes than others.
Hypothyroidism does affect heart rate and as yet you won't be on enough Levo or for long enough. That in itself will be causing you issues, that you are under medicated and still hypo. What you are experiencing today will be very different to a few months time, especially with further dose increases.
Is it possible that just being hypo is causing you sleep quality issues?
The other things to look at are vitamins. When hypo we get low stomach acid which means we cannot absorb vitamins well from our food, regardless of a great diet. For thyroid hormone to work well we need OPTIMAL levels of vitamins. Have you recently or could you ask your GP to test levels of ferritin, folate, B12 & D3?
Thanks for the advice, I will get my profile updated soon
I was prescribed 75 from the beginning and have only been taking this for 2 weeks. My decline in sleep quality (according to my watch) has only been since starting medication and my ‘stressful’ sleep appears to be because my heart rate is not dropping below 62bmp where previously this would have been 45(ish)bpm. I now wonder if my thyroid problems were the reason my heart rate was so low, but I have been very active over the last few year’s training for marathons etc.
I need to get to grips with vitamins and check my levels etc. as I am a vegetarian and have, for the last few years been experiencing what I believed to be IBS symptoms.
This is all so new to me (I didn’t even know what the thyroid did until a month ago) so lots for me to research.
I was a runner, similar heart rate. Got the T shirt for IBS and terrible indigestion, sleep disturbances and shopping list of hypo symptoms.
Went veggie for years, turns out I was lactose intolerant and gluten /grains caused me terrible trouble with my gut bacteria. I’m now low carb (but not keto) paleo.
I’m now 49, with a chronic ankle injury that has kept me off the streets for 4 years.
My best advice, take the diet and vitamins advice seriously and do your level best to sort out gut health, then advocate strongly for treatment for your symptoms with thyroid replacement hormones (this last bit happens very slowly it’s excruciating but if you rush you’ll end up in a mess so don’t rush).
And test yourself privately for all vitamins and thyroid hormones. Keep a spreadsheet and monitor the changes. Including av heart rate, resting HR and temperature on waking.
My best reads; Izabella Wentz (I have all her books all useful and full of post it notes) and Dr William Davies Supergut… I’ve only just discovered this, wish I’d heard about him 6 months ago.
Useful podcasts; Thyroid Answers Eric Baclavage and Let’s Talk Thyroid (Annabel forgot surname) both super helpful.
Heart rate, consider going slower when you do a dose increase, I took an extra 25 mcg every other day for a week, then every 2 days, then every day otherwise I got a bit sweaty. You could drop back to 50 for a week and see how that feels. Introduce the extra 25 when you feel more steady.
Other thing some of us do is take half the T4 dose at bedtime ( some take all of it) that’s really smoothed things out for me.
Best advice I was given, only change one thing at a time (E.g. diet or vitamin supplements) and give your body 2 weeks to adjust bed adding the next one.
If you’ve got nothing better to do read my bio for my journey so far, I am still very much a work in progress on gut health and energy levels but in a much better place physically and mentally than I was at diagnosis.
thank you so much for all the useful advice ☺️ I have lots of reading and research to do! It makes sense why my gut issues may have appeared in the last few years now, but I’ve never properly tried to get to the bottom of them, so now’s the time.
there is definitely a link between gut health and sleep. I’ve cut so much out but I now know if I have onions and garlic or beans / chickpeas in an evening meal I can’t get to sleep. I’m looking at SIBO again (thought I’d cleared it but not according to Dr William Davies Supergut) he does a 4 week protocol to follow, the hope is I can reintroduce the FODMAP fermenting foods that cause these symptoms. I’m on day 2 of week 2 I’ll report back. 😊
I think a heart rate of 62 is healthier than 45. Likely that very low heart rate was due to being hypo.
It's extremely common for changes in symptoms and sometimes worse symptoms in the early days of treatment.
Definitely as a vegetarian you will need to be all over the vitamin levels. Iron in particular can be difficult to raise. Have you been supplementing at all anyway? B12 is particularly important for you. If GP doesn't agree to test there are many private blood test companies. See this list with discount codes too. thyroiduk.org/help-and-supp...
You should be retested on your current dose 6-8 weeks from when you started it. Book blood test at 9am or as close as possible as this is when TSH is at its highest. Do the test fasting and take your Levo that day AFTER the test.
I've replied lower down too. My HR went up after 2 weeks also. I agree with others here who suggest it might be wise to titrate down for a little. If you've been subclinical or hypo for some time there's more likelihood of an impact on HR from the levothyroxine and your GP needs to take this into account. Have a look at the NICE guidelines on this.
I started on 50mcg of levothyroxine and felt a bit jittery to start with but eased off. When I went up to 75mcg I was a nervous wreck for weeks and heart beats did increase. I stuck with the treatment as the good people on this site said to do so. It eased off and started feeling good. I also had ibs for years and it went when I started treatment. Must of been thyroid causing it all along. Well it did ease until this Christmas and I had worst constipation I've ever had and full on ibs symptoms. It turned out I was under medicated and put me up to 100mcg . Ibs symptoms gone. For now! Stick with it and let us know how you get on
Yes, the medication itself could cause the rise in heart rate. I am regularly in the 90s and over a 100 at times now. This was never the case for me before my thyroidectomy (normal was 60s), and is there when my labs are in range & way out of range. Nothing changes with this rise in heart rate - from TSH less than one & a TSH recently of 32.
This happened to me and I went back to Dr and she reduced my med by 25mg and I didn't have again it takes so long to get to the right level which is right for your thyroid.
this is quite normal. I spoke to my specialist cardiologist about heart rate increasing with levo. His response was that heart rate and blood pressure increases it fluctuations are commonly due to hormonal changes or hormones. So that would make sense. But being over medicated sends my HR crazy
I like you am also an athlete, I race bikes and train hard.
Since being diagnosed with Hashimoto’s and being put on Levo I have experienced the exact same problems you have. I use to be at a sub 40 resting HR for years and am now at around 50 ish and my HR during workouts has also increased by around the same amount.
I had to change Levo brand. Mercury Pharma was giving me heart palpitations and leaving me breathless whenever I would ride my bike due to such a high HR even when cruising at Z2. I now only take Teva and Accord. My HR hasn’t come back down but my palpitations stopped. I think the very nature of Levo makes our hearts beat faster due to the medication trying to increase our metabolisms.
The biggest problem for me has been the weight gain. I’d hoped that starting Levo would have helped bring the weight down but it hasn’t
I’ve been on 125 mcgs since September FYI and am now trialling 150 on alternate days
Hi, great to hear from another athlete (although I wouldn’t call myself that 😅) I saw on your profile that this is a very new journey for you too!
I’m also finding my heart rate increase is having a negative affect on my exercise and making an ‘easy’ running pace feel more difficult! I don’t have palpitations like you but it’s certainly higher than it was before I started medication, although now questioning if my heart rate was because I was fit or hypo (without knowing).
I hope you get the weight under control soon, it’s hard to exercise so much and not feel it’s being reflected in the scales (even if that’s not why you do it).
Have you found many other differences in exercise since being medicated? I’m hoping I get injured less!
I have a heart condition and therefore take my HR regularly. Yes, it's a side effect of levothyroxine. My HR went up 10BPM on average with some spikes of tachycardia when resting within a month of taking levo. You're unlikely to get the spikes as you're doubtless fitter than I am. My GP stated that the increase was 'a clinically significant side effect' of the drug. In my case we chose to stay on my initial low dose for a further 6 weeks so as to let the heart settle down. If you're worried about this, challenge your GP as I'm pretty sure there will be literature on this out there. Also notice what your heart typically does during and after exercise. Does it increase and decrease overall? That's a good sign. Similarly when you've just woken up and about to go to sleep - is it a nice slowish rate that feels comfortable for you?
My situation is different from yours. See what others say. How you FEEL is always important I think.
Hypothyroidism can make your resting heart rate lower meaning that treatment can increase it back to where it should be. I run and when mine now drops to 48 - 50 it usually means my TSH has increased. I'm well controlled at the moment and my resting heart rate is low 60s and I feel much better. Low 60s is still pretty low. How much do you run?
It was sat consistently around 55bpm resting whilst I was training for 2 marathons, but then dropped into the 40’s this time last year when I cut my mileage right down (averaged over 24 hrs as I wear my watch at night too) I believe this change is likely due to me being hypo. Now it’s hardly going below 72 whilst I’m sat at my desk all day!
hi runner girl, I take 30mg tablets ( of Armour thyroid twice a week and was advised by my doctor to take it in the morning or early part of the day because it will give me heart palpitations. This bothers me so I cut the tablet in half and talk half in the morning with food and half in the afternoon thus avoiding the rapid heart beat.
Did you happen to have labs before you started taking it with food, Skylane? Just wondering if there was any difference since we are advised to be on an empty stomach. Simply curious.
from what I understand, food doesn’t make much difference ( although coffee might) just no B vitamins within 4 hours especially biotin. That vitamin seems to block the thyroid medicine 😊im not a medical professional and I’m only going by what works for me. Avoid flouride whether it’s your water or toothpaste. Flouride is bad for Hasimoto’s Thyroiditis. Get a good water filter pitcher that take the bad stuff out the city adds to the water(from the tap)my pitcher comes from Austria ( get on Amazon) with filters that last a couple of months each .
A GP who doesn't think an increase in heart rate is a consequence of starting thyroid hormone replacement ( especially when starting straight off at 75mcg dose rather than the usual smaller 50mcg dose ) .. needs to do some more reading about how thyroid hormones work in the body.
He could start here , as it's written specifically for GP's : healthunlocked.com/thyroidu.... (gps-told-keep-tsh-0.5-2pmol-l-hypothyroidism-causes-raised-cholesterol-thyroid-disease-effects-on-heart-and-cardiovascular-system)
To prove the point ~ the elderly/ or people with pre-existing heart conditions are usually started on even less ( 25mcg ) for precisely this reason ~ so as not to over stress the heart by the sudden introduction of a ful dose of Levo. Then the dose is gradually increased to the level needed once the body/ heart has had time to get used to the effects
"1.3.6Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.
1.3.7Consider starting levothyroxine at a dosage of 25 to 50 micrograms per day with titration for adults aged 65 and over and adults with a history of cardiovascular disease."
Well this is what I thought but as I’m so new to this I thought I would ask people with real experience and I’m amazed by how many of you have taken the time to respond, so thank you 😊
My heart rate is not ‘racing’ by any means but I’ve just noticed the slight increase that is affecting my sleep quality.
2 week is very early days where thyroid hormones are concerned...... give it some more before worrying about the heart rate issue ...as this may well settle down a vit over the next few weeks anyway .
you won' really know how this dose feels until you 've been on it at least 6 weeks , everything in the body takes time to adjust to and then make use of the higher level of hormone.
also ...over the next few weeks , the 75mcg dose will lower your TSH a bit ... this means your own thyroid will then make a bit less T4/T3 than it was doing ... so you may fell like you have a bit too much thyroid hormone just now, but in 3/4/5 weeks time you may feel like you have not quite enough again ... basically can expect to feel a bit different each week. until the dose is properly settled in .
If it was me and the heart rate was really bothering me ,then i'd consider lowering the dose to 50mcg for few weeks and going up to 75mcg later.
But if it's tolerable , then i'd consider just sticking it out and staying on 75mcg until the blood test.
When starting on 50mcg it is very common to feel nothing much for a week ,then a bit better for a week or so, then less good again. Then it's time for the 6-8 week blood test. and usually the dose need increasing to 75mcg ~feel a bit better ~ them less good again, blood test .. etc etc , Most people usually end up on somewhere between 75mcg -150mcg before they say feeling better.
Starting straight in at 75mcg shortens this tedious process , but it's a tougher ride for the body tp cope with .
A Helpful Quote from another members GP ,on what to expect when starting treatment for hypothyroidism.
"The way my new GP described it was ..."You know how your body is continually breaking down and rebuilding itself? Well, the thyroid controls the rebuilding, so if it isn't working you carry on breaking down but don't rebuild properly. Your body now has a lot of catching up to do, which will take a minimum of 12 months, probably a lot longer...." or words to that effect. He also said it would be a saw tooth recovery (get better, go backwards a bit, get better, go backwards a bit) and he's been right so far."
posting this unedited ..forgive typos.. sausages and mash have just appeared......
what a great way of explaining everything, thank you! I think being so used to looking at my ‘health stats’ from my watch everyday makes the smallest changes more noticeable, if I didn’t wear my watch 24/7 I probably wouldn’t even know.
Guessing I just phone up GP and book my own blood tests when due? I’ve only been prescribed 48 days worth of tablets.
did they come with a repeat prescription form in the bag ? ( there should be )
did the GP not say anything about needing a repeat blood test @ 6 -8 weeks when they prescribed them ? ( they should have )
So ...
~ you need to make sure you don't run out of tablets before you have a blood test. (the results will be messed up if you have not been taking them every day up till the test ) contact GP about a repeat prescription at least a week/ 10days before you are going to run out.
~Book a thyroid blood test for early morning ~ (preferably 9 am ish ) about 6 - 8 weeks after you started levo . ( to show highest TSH level of the day)
~On the morning of the test, don't take the levo tablet until AFTER the test. (giving a 24 hr gap from last dose ~ if you take Levo dose a couple of hours before the test, the fT4 result shows up as higher than it 'really' is for the rest of the day ).
~ don't have breakfast till after the test .( eating lowers TSH and you want to show the highest level)
GP receptionist won't agree that a 9 am/ fasting test is necessary for thyroid , often the only way to get one at that time is to say you can't make a later one due to work commitments....
Try to get all thyroid blood test in future at a similar time , so you can compare your results properly .
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Why does my heart rate increase so dramatically with gentle exercise?
On 100mcg Levo keep waking at 4am heart rate has increased. 
