is a low heart rate cause to be concerned? - Thyroid UK

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is a low heart rate cause to be concerned?

Thyroid_mum profile image
61 Replies

Hi all,

I’m on 100mcg Levo and 20mcg compounded IR T3 split through out the day and my resting heart rate is 50bpm.

it used to be 55bpm and I’m not sure why it’s dropped. Is this a reason for concern or indication of undermedicated ?

I’ve attached my results from end of January where I posted on here and was advised to increase T4 to 100mcg from 75mcg and my heart rate is lower, which is weird.

Any advice would be appreciated 🙏🏼

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Thyroid_mum
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61 Replies
TiggerMe profile image
TiggerMeAmbassador

I've heard other people say that this happens to them when they are over replaced as well as under replaced... perhaps alternate 100/75 and see how this effects you HR?... your results are at the low end but perhaps that is where you need it to be and a little bit of fine tuning is needed 🤗

humanbean profile image
humanbean

Just for info, the medical name for having a heart rate under 60 beats per minute is Bradycardia. It's never been a problem of mine so I haven't researched it.

en.wikipedia.org/wiki/Brady...

SlowDragon profile image
SlowDragonAdministrator

ALWAYS

T3 ….day before test split T3 as 2 or 3 smaller doses spread through the day, with last dose approximately 8-12 hours before test

Suggest you try reducing T3 by 5mcg and increasing levothyroxine by 25mcg

Ideally you shouldn’t change both at once

So you could try reducing T3 first

Thyroid_mum profile image
Thyroid_mum in reply toSlowDragon

Why would I reduce T3? Surely low heart is under medicated?

SlowDragon profile image
SlowDragonAdministrator in reply toThyroid_mum

Well your Ft4 is low …..perhaps too low

If you increase Levothyroxine further Ft3 might go too high

You could try increasing levothyroxine first

Why are you taking compounded T3 ?

Have you tried Thybon Henning T3

Have you done Dio2 gene test?

Thyroid_mum profile image
Thyroid_mum in reply toSlowDragon

Yea, I have DIO 1 and 2 mutated genes so don’t convert well. Did compounded coz I couldn’t handle T3 very well and did and had to build it up really slowly. The T4 level above was on 75mcg T4. I upped to 100mcg and haven’t retreated as it’s not 6 weeks yet. The T3 is split in 3 doses, 10mcg am, 5mcg lunch and 5mcg bedtime.

SlowDragon profile image
SlowDragonAdministrator in reply toThyroid_mum

I upped to 100mcg and haven’t retreated as it’s not 6 weeks yet.

Oh well….wait and see if levels have improved

Thyroid_mum profile image
Thyroid_mum in reply toSlowDragon

6 weeks is next week so I post my results then

Moonchild10 profile image
Moonchild10 in reply toThyroid_mum

Do not reduce T3.

McPammy profile image
McPammy

My heart rate lowers when I’m over medicated. It has dropped to as low as 37bpm resting. I was over medicated at that point on levothyroxine. I didn’t know what was happening. I reduced my levo dose and I was fine again. My resting hr is usually around 55-58.

Thyroid_mum profile image
Thyroid_mum in reply toMcPammy

thanks McPammy, I will retest next week and see where my levels are.

Moonchild10 profile image
Moonchild10 in reply toMcPammy

over medicated does not cause lower heart rate! No way. Being under medicated can make the heart rate go up because it’s working harder, especially when walking up a hill, etc. But I have not heard of low heart rate = over medication.

TiggerMe profile image
TiggerMeAmbassador in reply toMoonchild10

I'm with McPammy my resting heart rate also drops when over replaced

Thyroid_mum profile image
Thyroid_mum in reply toTiggerMe

I’m definitely not over medicated as I have hypo symptoms. I’ve upped to 30mcg of T3 and it’s the same pattern, I upped by 2.5 for a week and initially the resting heart rate increases to 55/56 and then after 3 days it drops again to 50/51.

TiggerMe profile image
TiggerMeAmbassador in reply toThyroid_mum

Sorry old post but replying to Moonchild really, things I'm sure have moved on for you, did you increase your T4 as previously you'd mentioned your heart rate was better when on T4? Also in the last few results posted your Vit D is also on the low side, ideally 100-150 so this could be causing you some issues

Being over replaced can also present as hypo symptoms it depends how your body reacts really 😕

I upped by 2.5 for a week and initially the resting heart rate increases to 55/56 and then after 3 days it drops again to 50/51

This makes me wonder if your body is actively binning off the extra T3? 30mcg is a big dose of T3

I see you are a T3 dose splitter, have you ever tried a smaller single dose (15mcg)?

McPammy profile image
McPammy in reply toThyroid_mum

Remember over and under medication can have very similar symptoms.

Moonchild10 profile image
Moonchild10 in reply toTiggerMe

The more logical explanation is that you’re converting to RT3 instead of FT3, which makes you more hypo, hence the lower heart rate.

TiggerMe profile image
TiggerMeAmbassador in reply toMoonchild10

But rT3 is made from excess fT4 rather than fT3? T3 can't be converted to rT3

Sorry without reading the whole thread I've rather lost the thread... weren't we discussing too much T3?? 🙃

Perhaps this was meant for  McPammy as she has found that too much T4 lowers here heart rate?

Moonchild10 profile image
Moonchild10 in reply toTiggerMe

Your resting heart rate drops because your T4 is converting to RT3, which makes you more hypo.. not hyper. It’s not called being over medicated, it’s called having too much T4 convert to RT3. I can’t believe anyone would think low heart rate means top much thyroid hormone, it’s more so too much of the wrong (T4) medication.

TiggerMe profile image
TiggerMeAmbassador in reply toMoonchild10

My experience is if my T3 dose is too high my heart rate lowers..RT3 doesn't do anything so why would it make you more hypo it is just binning off excess fT4?

I don't quite understand why you insist on telling myself and    McPammy something we know isn't true for us? We can all only offer our experience

We don't seem to know much about you other than you have a thing for rT3? Perhaps if you filled in your bio it would be helpful?

McPammy profile image
McPammy in reply toMoonchild10

I am living proof that over medication, whether it’s T4 or T3, can significantly lower your resting heart rate. 37bpm I was over medicated with T4, once T4 reduced my heart rate went back to my normal 57bpm with Hashimoto’s even though my T3 was too low still. That was observed and documented while on a cardio ward for a week wearing a monitor, blood tests etc. I’m afraid you are wrong. It’s about balance and getting the levels right for you. T4 and T3 need to be optimal just like a healthy persons levels. You cannot say it does not because it does. This might not happen with everyone but certainly does with me.

Moonchild10 profile image
Moonchild10 in reply toMcPammy

you can’t be over medicated if your FT3 is low.. the more logical explanation is this: The T4 medication was raising your RT3 instead of FT3, which would make you more hypo, hence the lower heart rate. You feel better reducing T4 because it’s reducing RT3, which in turn will raise your heart rate to what it was before. Again, T4 can convert in RT3–which makes you feel super hypo. There has never been a case where lower heart rate = hyper, especially with low thyroid levels. It’s just not logical.

tattybogle profile image
tattybogle in reply toMoonchild10

There has never been a case where lower heart rate = hyper, especially with low thyroid levels. It’s just not logical.

'never' is a strong word moonchild,

first 2 entries entry on google found these . so it is clearly possible : ncbi.nlm.nih.gov/pmc/articl.... Hyperthyroidism and severe bradycardia: Report of three cases and review of the literature

academic.oup.com/qjmed/arti... Bradyarrhythmia as a presenting feature of subclinical hyperthyroidism

mona.uwi.edu/fms/wimj/artic... Subclinical Hyperthyroidism Presenting with Bradycardia-associated Syncope

Thyroid_mum profile image
Thyroid_mum in reply totattybogle

When I was on 200mcg of T4 my heart rate was 65-70 bpm.

Now that I’m on a lower dose of T4 and T3, my heart rate is lower. So I don’t think the over medicated scenario applies to me on this case

Moonchild10 profile image
Moonchild10 in reply totattybogle

low heart rate = hypo. If someone’s heart rate decreases on T4, either med is too low, or, they’re converting T4 to Reverse T3.

tattybogle profile image
tattybogle in reply toMoonchild10

am not interested in arguing about it moonchild , i suggested some reading to broaden your knowledge base ,as i thought your 'never' reply was too black and white, when as any observant person knows , thyroid is rather more nuanced and individual than that.

Moonchild10 profile image
Moonchild10 in reply totattybogle

it didn’t mention thyroid hormone though, that’s very different.

McPammy profile image
McPammy in reply toMoonchild10

I was over medicated on T4 at the time whilst my T3 was only 8%. I can barely convert to T3 from T4. It doesn’t matter if it’s too high T4 or too high T3 for me. I’m now on T3 medication combined with t4 liquid levo. You will just have to believe me as it’s documented in a hospital setting. Even now years later my heart rate plummets if my ranges either one get too high for me. Last week it was 46bpm I knew I was feeling over medicated as I was sleeping poorly. As soon as I dropped a T4 dose the following day I felt better. I’m sorry you disagree but it’s true in my case.

Thyroid_mum profile image
Thyroid_mum in reply toMcPammy

I’m not disagreeing with your case. I’m saying I don’t think it’s relevant to me because I’ve been on a much higher dose of T4 and I didn’t have a low heart rate.

I don’t think 30mcg of T3 is a high dose either.

So I am not over medicated.

McPammy profile image
McPammy in reply toThyroid_mum

I don’t think I replied directly to you.

Moonchild10 profile image
Moonchild10 in reply toMcPammy

Yes, as soon as you dropped the T4 dose, I believe you. T4 can make you more hypo, it goes to RT3, so it makes sense that you feel better dropping T4. It’s not because you were hyper.

McPammy profile image
McPammy in reply toMoonchild10

I’ve never said I was hyper. You are getting mixed up. I cannot continue this thread. I’m trying to watch tv and relax.

Moonchild10 profile image
Moonchild10 in reply toMcPammy

When I was on Nature-throid, my Reverse T3 skyrocketed with a good level of FT3, I felt terrible. If I had seen a conventional doctor, they would have thought that I was over medicated! I was on two grains of Nature-Throid, with 35 mcg T3. My Reverse T3 went from 11 to over 25! As soon as got off of the T4 and increased the T3, all of my hypo symptoms went away and my Reverse T3 returned to normal. I now do well on 75 mcg 2 times a day.. no hyper symptoms at all.

Moonchild10 profile image
Moonchild10 in reply toMcPammy

yes, “overmedicated” with T4 can make you more hypo.. because you may be converting to RT3. I converted to both, FT3 and RT3. Have your RT3 checked! You won’t feel better with a low T3, unfortunately.

McPammy profile image
McPammy in reply toMoonchild10

My rT3 was checked by my private endocrinologist and it was normal. It has been checked before also. For me it’s too high T4 or it can also be too high T3. I know as I’ve had bloods done when the heart rate was very low 37bpm and I was over range with T4

Moonchild10 profile image
Moonchild10 in reply toMcPammy

Conventional RT3 range is off, it should not be over 14.

Moonchild10 profile image
Moonchild10 in reply toMcPammy

”normal” and “in range” is not optimal.

McPammy profile image
McPammy in reply toMoonchild10

I’m sorry but I can’t answer you anymore. I’ve given details of my low heart rate and why.

Moonchild10 profile image
Moonchild10

The T4 could be making you more hypo by converting to RT3, which would make sense why your heart rate dipped. It’s not because you were over medicated.. your FT3 is low you say, so that’s not over medicated.

Thyroid_mum profile image
Thyroid_mum in reply toMoonchild10

my reverse t3 is 18. the reverse T3 conversion ratio is 0.25

Moonchild10 profile image
Moonchild10 in reply toThyroid_mum

RT3 should be no higher than 14, per Dr. Child’s.

Moonchild10 profile image
Moonchild10

Hi there—have you had your RT3 looked at? When I was on Nature-throid, my Reverse T3 skyrocketed with a good level of FT3, I felt terrible. If I had seen a conventional doctor, they would have thought that I was over medicated! I was on two grains of Nature-Throid, with 35 mcg T3. My Reverse T3 went from 11 to over 25! As soon as got off of the T4 and increased my T3, all of my hypo symptoms went away. I now do well on 75 mcg 2 times a day.. no hyper symptoms at all.

Incoguto profile image
Incoguto

I'd check labs if you can. That's a hefty 25mcg T4 added, if you're not converting well, it's bound to give you issues. Most likely adding 25 t4 lowered your tsh more, so peripheral conversion isn't the same.

If at any point we add t4 to t3 and become too much for our body at that given time throughout the day, the system will flush out hormones/degrade them. That would make you feel more hypo. Tania Smith has done excellent posts about it on thyroid patients Canada.

Or you are simply just still hypo.

Overmedicated unlikely, but I'd say the balance is wrong.

Might have made sense to add t3 instead of t4 few weeks ago if you have DIO enzyme issues. It's not all about how good numbers look, but when you personally feel well.

Thyroid_mum profile image
Thyroid_mum in reply toIncoguto

Thank you, I’ll check it out. I do have recent labs. I’m on 75mcg of T4 and 30mcg of T3 (T3 split into 3 doses of 10 mcg throughout the day) my T3 is still low at 13 hours between meds. At 100mcg of T4 and 25mcg of T3 my T3 wasn’t any better at 4.0 so T4 doesn’t convert well. I’m wondering if I should try T3 only.

Latest results
TiggerMe profile image
TiggerMeAmbassador in reply toThyroid_mum

I'll pick up on your very low cortisol level are you taking any adrenal support? Good levels of cortisol are needed for thyroid hormone uptake

Thyroid_mum profile image
Thyroid_mum in reply toTiggerMe

This was at 9am. I’ve done multiple 4 point saliva tests, cortisol is good until 11 when it’s supposed to drop but doesn’t until later and it’s lower in the evening. I take nasal spray RSG3 for adrenal support and seriphos at night

Incoguto profile image
Incoguto in reply toThyroid_mum

Your ft3 ft4 are really low, that would make your cortisol low too , no wonder your pulse is low

Thyroid_mum profile image
Thyroid_mum in reply toIncoguto

I’m slowly increasing T3. Not bothering with low T4 as I don’t convert

Jaydee1507 profile image
Jaydee1507Administrator in reply toThyroid_mum

Even people who don't convert still need their FT4 at around 70% of range.

Thyroid_mum profile image
Thyroid_mum in reply toJaydee1507

If you don’t covert T4 what is the necessity of T4?

I’m leaning towards T3 only as symptoms are the same at 100mcg or 75 mcg.

My levels of T3 do not increase at all on higher dose of T4

Jaydee1507 profile image
Jaydee1507Administrator in reply toThyroid_mum

If you suddenly dropped all your Levo then you would notice a difference. Even though its not converting to T3 it has a role to play even if its just filling space in cells.

People on combination therapy are generally those who dont convert well and its fairly standard for most people to need both FT3 & FT4 at around 70% of range.

Its not really to do with whether your Levo is converting.

Thyroid_mum profile image
Thyroid_mum in reply toJaydee1507

What about all the conflicting information of reverse T3? It’s all so frustrating and confusing

Jaydee1507 profile image
Jaydee1507Administrator in reply toThyroid_mum

I wouldnt worry too much about RT3. Millions of people do well on combination treatment. RT3 is a red herring and raised levels can be caused by a number of other things not related to thyroid.

Thyroid_mum profile image
Thyroid_mum in reply toJaydee1507

Why do so many say reverse T3 blocks your cells from getting T3? 😵‍💫

helvella profile image
helvellaAdministrator in reply toThyroid_mum

Because it used to be said that is what happened. They were wrong. And that includes an awful lot of pages (paper and web) many of which were written by doctors.

It was something that looked like a reasonable idea. Until someone actually looked properly.

Deiodinase Type 3, not RT3, plays the T3-blocking role

thyroidpatients.ca/2019/11/...

RT3 inhibits T4-T3 conversion. How worried should we be?

thyroidpatients.ca/2019/11/...

Thyroid_mum profile image
Thyroid_mum in reply tohelvella

Thank you, will try digest the info ☺️

Thyroid_mum profile image
Thyroid_mum in reply tohelvella

Does T2 supplements help speed up metabolism? Or is that a gimmick for naturopaths to make money?

helvella profile image
helvellaAdministrator in reply toThyroid_mum

My view?

Someone has sourced T2 and is selling it. If it had gone through all the trials, etc., that would be expected of a new thyroid hormone medicine, it would be prescription-only. But as it hasn't, vendors are into making hay while the sun shines.

3,5-Diiodo-L-Thyronine (T2) in Dietary Supplements: What Are the Physiological Effects?

ncbi.nlm.nih.gov/pmc/articl...

But this is based in scepticism and cynicism - not knowledge or understanding.

Moonchild10 profile image
Moonchild10 in reply toIncoguto

Tania is amazing and very intelligent!

Bayoubilly profile image
Bayoubilly

What has helped me get my thyroid levels optimised is Knowing the symptoms of both hyper and hypo conditions. Knowing that the body need IODINE to make Thyroid Hormones. Knowing what temperatures are reflected when the body is running hot (Hyper) and running cold (Hypo). Knowing that Hyper =fast heart rate and Hypo =slow heart rate. I WAS diagnosed with an Overactive thyroid over 13 months ago. Was prescribed Carbimazole, and propranalol, After getting all my nutritional and vitamins & supplemental issues sorted as well as going TOTALLY gluten, grain and dairy free I was able to get Both T3 and T4 optimised. But NOTHING would get my TSH to even register on the scale. UNTIL I started taking 12 mgs (4 drops) of Lugol's 5% Iodine. In less than a month my TSH levels went up from 0.015 to 2.67.In addition to having had two independent MEDICHECK Thyroid checks and in conjunction with NHS protocols, I decided to USE my body as my own guinea pig and STOP blindly following the NHS. I have decided to stop taking my last 5mg of Carbimazole and as of today I gave stopped taking the Lugols 5% Iodine. I am scheduled for a NHS retest in October. I go by my energy levels, How I FEEL, my resting heart rate and digital thermometer to measure my basal body temperature. I use a FIT BIT watch to continually measure my Resting heart rate. Prior to taking the Lugols 5%, my resting heart rate was 72 bpm. With Normalised T3, T4 and Low TSH. Basal Body temperature was 36.2-36.6. After I started taking Lugol's 5%, everything normalised, Basal Body temperature reduced to 36.0-36.4. Due to a T3 reading of 3.1 (low end of scale) I decided to STOP Lugol's 5% and just monitor my heart rate, and Basal Body temperature. ONCE you know your body, and how your thyroid works, using the resting heart rate and digital thermometer, you can have a better indication of what's going on in your body. STOP focusing so much on meds. Focus on how you feel and what happens to your body when you increase or decrease meds. Using the resting heart rate and thermometer are tools you can use. I am no longer taking any prescribed medicines. YES I did this without consulting either my GP or Endo. WHY ? They NEVER told me anything about what I could do to mitigate my condition. The Endo said that there was NOTHING I could Do. It was my genetics. Be your own health advocate. This Forum is Good. But Don't follow it blindly either.Use your GOD given common sense and intuition. What I did works for me. Find out what works for you.

tattybogle profile image
tattybogle in reply toBayoubilly

the impact of Iodine on thyroid is complicated, so for general interest i'll add a link to this collection of information about iodine / thyroid : healthunlocked.com/thyroidu... /iodine-a-collection-of-useful-information-because-the-search-facility-on-health-unlocked-is-totally-pants

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