Low resting heart rate

[Sturmundcalm]

I realised last year that my BP/resting heart rate are quite low. I had a few dizzy turns while doing strenuous exercise (as I would stand up mainly) which is why I checked. Got a Fitbit in February and my normal range for RHR seems to be 58-63. Went up a wee bit when I had covid in March but then came back down.

I've been to the GP a few times in the last 18mmonths over how cold I feel - I'm always wearing more clothes than other people and have hit the point where in winter I'm not doing things (like going out a hillwalk) when the temperature is below 2-3 celsius cause I just can't face getting THAT cold.

Have been told that all my thyroid tests are normal - that seemed the most obvious cause as I have family history, Raynauds, thinning hair, am overweight, etc. Most recently got checked for iron and GP has now put me on iron tablets as I'm within the normal range but towards the very bottom.

Ten days after starting the iron tablets and my RHR has dropped a wee bit more (56 the last couple of days, 55 today). I've also had a headache or been "on the edge" of a headache for the last week.

Anyone got any ideas how I could get my heart rate to go up a bit? Could it be that causing my headache-y feeling?

Go back and ask for more thyroid tests.

Ask for :
TSH
T3
T4
rT3
Iodine
TPO antibodies

Thyroid testing is woefully inaccurate and I would bet my front teeth it’s your thyroid. You have all the classic symptoms.

Have you informed your GP about your feeling faint. It's best to get it checked out. I had similar and wore a monitor for a day or two to check my heart rate which is a similar range to yours. It was decided I suffered with vasovagal syncope so was given advice on how to cope with it.

Have you had an ECG?

thanks everyone. despite being v capable overall I tend to be one of those folk who struggle to be assertive with medical staff...

i have mentioned my heart rate a few times but the dizziness was only 3-4 times and none of the GPs I've seen have taken any interest in it. last GP did take my HR/BP while i was there but it was more in the normal range - not least cause I hate being there!! so no ECG or any kind of monitoring ever suggested.

i will try to push for more thyroid testing. the problem is that i've worked really hard over the last 5-10 years to lose weight and get fit so overall i'm doing ok but I think what's really frustrating is to end up that i still feel knackered and cold all the time - and considering the symptoms and the scale of family history (mum, all her sisters, my sister, 4 cousins) i struggle to believe that my thyroid is fine BUT they have done the basic TSH and T4 tests a few times over the last 10-15 years and always comes back within normal range.

Your heart rate is probably low because you got fit and lost weight

I did the same and mine is now between 49 and 53.

I have to be careful when I stand up quickly or after a bath for example! But that's more to do with low Bp which runs in my family. Did they take your blood pressure?

(I mean more than once not just the one time)

My RHR is between 47 and 51 - I'm pretty fit. I don't feel dizzy etc or worry about it. I exercise v regularly

Thats not a particularly low heart rate, mine is 54 - 60 resting. Athletes apparently have low hearty rates too !

Phew Fitbit tells me my resting rate is 55

Agree with PP - the RHR on it's own seems perfectly normal - in fact pretty much the same as mine - which is probably why the GP isn't more interested in it.

If your TSH and T4 levels are normal then you will not be prescribed treatment for hypothyroidism. TPO antibodies alone are useless as a large percentage of people will have positive antibodies but normal thyroid function test. They are only useful if your TFTs show hypothyroidism as Hashimoto's thyroiditis is the commonest cause of hypothyroidism in the developed world. Iodine deficiency is the commonest cause worldwide but you'd have to be seriously malnourished for this to be the cause as iodine is found in a lot of foods. Your HR is only slightly lower than the lower range of "normal" but coupled with the dizziness may be caused by something cardiac so I suggest initially a 12 lead ECG which they can do in the practice and then referral for a 24 or 48 hour tape. They can also check your lying and standing blood pressure to make sure there isn't a significant drop causing dizziness.

RHR on fitbits tend to be lowish I find. Mine is 58 counting myself, but 55 on the fitbit. Both the thinning hair and the dizziness (low bp) could well be from the low iron. Not sure what your weight loss is but if you are losing weight and aren't eating enough that makes you feel cold.
I'd agree with pushing for more thyroid tests, a couple of friends with thyroid problems and all the classic symptoms took years to get a diagnosis and their health suffered because of it. With iron and thyroid just because you fall within a range doesn't mean that that is the optimum level for you. You'll need to get assertive otherwise they won't care.

thanks all - taking on board all the feedback and it is reassuring to hear there are plenty of folk with lower RHR.

trying to answer q's/comments:

• weight loss was deliberate - am about 6 stone lighter than I was at my heaviest, lost it over a period of about ten years and have been fairly stable at this weight for three-four years. i'm still a stone above a healthy BMI though! would like to lose another stone but finding that absolutely impossible. the cold feeling has only really kicked in over the last 18 months and was substantially worse winter just past than the one before (e.g. I coped with walking in -5 celsius weather Jan 2021 but struggled at 0 celsius Jan 2022)


• i guess the RHR bothers me cause according to Dr Google it is lower than "normal", and considering i'm an overweight 48yo who is fit but not an athlete I think it's more likely to be related to how cold I feel...


• my BP is on the low side but within "normal", RHR shows as pretty much the same on the BP monitor I have as it does on the fitbit. just double-checked it and Fitbit actually measured my current HR as 59 while monitor showed it as 58. my BP was 91/64.

The GP seemed to be suggesting at one point that the cold might be caused by peri-menopause. And I think it's perfectly possible I'm peri-menopausal but never heard of that causing people to feel cold all the time...

Your heart rate isn't lower than normal.

as I said - according to Dr Google it is... British Heart Foundation: "A normal adult heart rate is between 60 and 100 bpm while resting."

I would also consider your RHR as normal.

Mine is around 48 - and I’m 44 and not particularly fit (ie I’m no athlete). Ignore dr google.

Just bin the fitbit! I have never had any idea what my heart rate is because it's not something any of us ever needs to know. Once you start looking for imaginary problems, then you'll find them.

yeah the issue is that I'm freezing the bulk of the year and wearing at least one layer if not two more than virtually everyone else at any given time. it's hitting the point where it's impacting on my ability to go about my business over the winter. so the RHR isn't the issue I'm trying to fix but I'm concerned it plays a part - I think most folk don't have gloves in their pockets in June...