Thyroid UK
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T3....Too little or too much? Odd cardiac goings on and the jitters...2 questions!

Hello again! Now on 38 mgs t3 (split into 2 doses) and 50mcg t4 on waking since Feb. Feeling slightly better this week but fatigue lingering,cold hands and feet,still gaining weight.

However at night-time i am waking up after about an hours sleep with an odd, slightly pounding,erratic and racing heart. It is quite uncomfortable and i fidget about for about 45 mins ish before sleeping again. I have been sleeping soundly up til now.

In the day even slight exertion, very quickly causes my pulse to race, making me quite out of breath. My resting pulse is normally around 76bpm and blood pressure on average is 120/66 ish. Has anyone a clue as to what may be causing this? Its quite worrying.

Ive also noticed an inner shiver/jitter which i notice more in the evenings and is worse after eating (i think).I returned to work hands shook all day !

Today i went out for the day completely forgetting all my meds (poor memory) and this evening im still jittery so can it be tissue overstimulation by the t3???

Thanks for any help received.........K x

30 Replies

sounds more like cortisol and blood sugar imbalances.

try to follow a 'low GI' diet very very closely for a few days


Hi yes i will try seems worse in an evening after our main meals so going to try smaller more regular meals (and less choccie) x x xThank u


Well done for getting back to work, bet that was hard.... I know it was for me....

Sorry I know nothing about effects of T3 (or evenT4) yet, but have had the jitters & inner tremor for years, a PT op has lessened it, but still there sometimes - so not necessarily the meds?

I don't know of course - but Dr Lowe did say something about your metabolism kicking back in? Hang in there, it must get better, but if your'e worried cut back a bit maybe? trust yourself Jane :D


Hi Jane.....its been much better since ive spread out the doses to 3 per day 12.5mcg each.

The mental side of facing going back was hard as i felt quite unwell when it was decided, but i do feel brighter this week. Its so up and down though. Im trying to avoid going to my clueless gp as i dont want to seem a hyperchondriac and she will only blame the t3!

Thanks x x x


It is possible it's overmedication. When I was on 200mcg T4 and 50-60mcg T3 I got a shake in my hands, wobbly legs and an occasional extra thump of my heart when lying down at bedtime, which went away after a short time (unless I got anxious about it, then it lasted longer!! :-P) I also still had some bad hypo symptoms.

When I went down to 47.5mcg T3 with 200mcg T4 I still had the hypo symptoms but didn't have those shake and heart symptoms.

What I needed was more T3 (which works a lot better for me) and less T4. So now I'm on 67.5mcg T3 and 75mcg T4. Most of my hypo symptoms are gone and no overmedication symptoms.

So maybe you would feel better on less T4 and more or the same T3?

But you've also felt bad after not taking your T3 for a day. So maybe it isn't overmedication.

I also had a thumpy heart due to too much sugar.

I've been having the occasional heart thump off and on for a couple of months. I worried that it was too much T3 but it also happened on a day I'd forgotten to take my afternoon dose. So it couldn't be that. It only happened in the evening too.

When I get anxious I comfort eat sweet sugary things and almost always in the evening. Since I've been trying to do more things lately to get me back into life towards working I've been comfort eating more. I worked out these big sugar rushes was giving me the heart thump. Since I cut down on them, particularly in the evening when not being physically active, then I haven't had a thump since.

Hope this helps,

Totoro x


yes totoro, about the sugar 'rushes', sometimes they can be a lot less obvious than we think, ie: not necessarily eating 'sweets'. I never eat sweets but was still getting rushes from less obvious foods. I have not been good with my paleo diet and have been having the odd carbs, if I had the carbs 'alone' (ie rice) I'd get the sugar rush, if I had it with protein then no, I recently invested in a small blood sugar monitor, when my heart is pounding my blood sugar is above 8 mmol when it is not my blood sugar is never above 6.1 :)


Hi It wouldnt suprise me if it was sugar and i have cut down a lot....i havent experienced the wakenings again yet since i posted. Its also better since ive spread out the doses to 3 a day...I shall continue to monitor it all though :) Thanks xxx


babycatcher, I remember you had a very hard time getting your T3 and had reduced your T4 by 50mcg around/just before Christmas in anticipation of it arriving -but it did not, but nevertheless your system must have been T4 deprived for some time and so is having, I think, problems adjusting to your meds.

Perhaps you will, ultimately, need the totality of the medication you are having but the T3 especially might just be too much initially for a relatively starved system, being suddenly delivered to that system in 2 doses of 19mcg each. 19mcg per dose is very roughly the equivalent of 76+ mcg T4, but T3 is faster acting with a shorter halflife than T4.

I have T3 = T4, and had this problem of erratic heart action, but it was solved by dividing the T3 into 3 daily doses so there was a more constant T3 stream going more gradually into my system. Taking your T3 in 3, or 4, smaller doses would result in a less fluctuating input which might have the effect of calming the heart, etc. effects.

Alternatively, cut the T3 dose by one third or so, take the smaller overall dose in 3 or 4 doses daily for a week, then introduce the remaining T3 as another dose. Right now it could be that you are (relatively) hammering an unaccustomed system/metabolism and a more gradual approach to your intake of T3 is called for.

Also Dr Lowe said people with Hashimoto's who cannot tolerate meds.and have any of these:palpitations, rapid heart rate, tremors, panic attacks, low or high blood sugar,symptoms of overstimulation, hyperthyroid, but still feel hypo, usually means a vitamin B deficiency as thyroid meds take away B vits so hypos need more B vits.

You had extreme stress when your first T3 delivery was fouled up, B vits would be used up dealing with this stress. Your reaction ties in with nbd's advice re cortisol and low blood sugar, another adrenal stress. nbd's advice to seek a low GI diet to deal with low blood sugar issues is good advice, and Dr Lowe's advice about B vits is easily followed.

Hope this helps


Hi nostoneunturned,

I have hashimotos and have my blood sugar becomes high when taking thyroid meds,so how much vit B should be safe to take per day as I donot take any vit B.

Thanks in advance.


Hello, nono, regarding B vits and high blood sugar I took Dr Ray Peat's advice that most supplements are of low quality and so I ensured that I had a high Bvit intake by using brewer's yeast in soup, Marmite/Bovril, good sources B vits themselves, casseroles, and having not just a sprinkle of wheatgerm on cereals but a couple of level dessertspoons of wheatgerm (source of B vits) ladled on cereals. Also devised a recipe for lazy woman's pudding: lot of wheatgerm in base of dish, apricot juice next used to soak said wheatgerm, thin layer fine marmalade, then thick layer of dried stewed apricots, then layer of thick greek yoghourt, sprinkled with hefty dusting of carob powder or cocoa powder if liked. My kind of hassle free non-cooking, more of an assembly job. Just stuffed with B vits and potassium, both from wheatgerm, and other good things, iron, etc., for instance, from the apricots, and calcium and B12 from the yoghourt.

Then I also used a multi-B vits only supplement from health shop just to make sure. Bit of a belt and braces approach, even if I am the wrong gender for that saying. I did not know that safety was an issue re B vits, except in supplements B6 should be balanced by equivalent amount B2, but if your diet is stiff with B vits this should not be an issue. Liver and chicken liver have B vits, especially B12 and folate, have iron also.

Look after your B12 intake, get it checked, ought to be over 600 at a minimum, hypos are very liable to be low in that. Microwaves destroy vitamins and enzymes remember, do not cook or reheat in it regularly. Sorry, I'll vacate the soapbox now.


Hi Yes it all makes sense...but this time it wasnt hard to know where to start. Ive followed your advice and spread the doses out and its been much better having a stream of t3 going through in the evening...ive increased my b vits a tad as im on a fair amount anyway and ive ensured a proper adrenal routine as it was getting a little sloppy. Ive cut down on sugar and eating smaller regular meals too. So fingers crossed!

1 like

oh that reply was for nostoneunturned! lol


Hi Atrial Fibrillation,( A.F.) an arrythmia is more noticeable at night. You need to take your H,R, ( pulse) when ever you feel funny. Is it uneven? It is very noticeable. If it is ,also take the HR other times during the day. Keep records. This is the normal first diagnosis for AF. AF often occurs earlier if thyroid disease. It is very common. The next step is a home monitor for HR it does tiny ECG s . A normal ECG will not show this as an intermittent problem for years ,often for ever. Home monitor ( GP or cardio) is best if 7 day but if not 24 hours ( more likely).If bad then you need to see an arrythmia specialist cardio. It is not too serious but does need monitoring, there is treatment if gets bad, The most important thing is that you need anti coagulation as the main problem with AF is clots. Anticoagulation makes the risk a great deal lower.I hope this helps,if AF it is really not too serious and very common.



Hi Jackie! I keep good records of vitals for Dr Ps diaries and my pulse varies alot depending on how, where and what ive been doing. First thing it can be 62 and by the time ive stood up its racing at 85-90bpm. I will invest in a ecg type monitor before i speak to gp as she will just blame the t3! Thanks K xxxx


Hi Jane, If Dr. P can no longer refer you to any one, you need to go to the GP with the records, it is the swinging and palpitations that matter.If you do two consecutive HR`s when "funny "If it is AF it will show the swinging clearly. The only way is to take the pulse it is what the doctors do initially. The pulse/HR in the neck is the easiest. Do not use your thumb as that contains a pulse of it`s own. None of the tested monitors are tested for HR just approved for BP. I made extensive enquiries not long ago, manufacturers, BHF etc. All the docs even and of course, the cardios say that they are useless. Do your HR for 15 secs then multiply by 4. Normal HR should be 60 to 80. It can vary , make sure you have rested 10 mins and it is really the swinging you are looking for., It should be Ok with the GP ,i have very major lethal cardiac conditions and I am on T3, so long as the FT3 is in range, even only just.None of my own cardios or the ones in hospitals query it.

Best wishes,



I feel that the heart issues need to be looked at. That is quite a high pulse pressure.

I know not the perfect resource, but Wiki does have some pointers:

All the best



sorry Rod what is high? the pulse at 76 or the blood pressure at 120/66? to me both seem normal?


Don't know what happened there - I responded but my reply has not hit the site! If there is a duplicate, apologies.

Pulse pressure = systolic minus diastolic.

That is, 120 - 66 = 54.

Some sources suggest that 40 is the point at which it becomes an issue.



That link says this:

Pulse pressure: An indicator of heart health?

What is pulse pressure? How important is pulse pressure to your overall health?


from Sheldon G. Sheps, M.D.

Blood pressure readings are given in two numbers. The top number is the maximum pressure your heart exerts while beating (systolic pressure), and the bottom number is the amount of pressure in your arteries between beats (diastolic pressure). The numeric difference between your systolic and diastolic blood pressure is called your pulse pressure. For example, if your resting blood pressure is 120/80 millimeters of mercury (mm Hg), your pulse pressure is 40 — which is considered a normal and healthy pulse pressure.

A high pulse pressure may be a strong predictor of heart problems, especially for older adults. Generally, a pulse pressure greater than 40 mm Hg is abnormal. A pulse pressure lower than 40 may mean you have poor heart function, while a higher pulse pressure may mean your heart's valves are leaky (valve regurgitation).

The most important cause of elevated pulse pressure is stiffness of the aorta, the largest artery in the body. The stiffness may be due to high blood pressure or fatty deposits on the walls of the arteries (atherosclerosis). The greater your pulse pressure, the stiffer and more damaged the vessels are thought to be. Other conditions — including severe iron deficiency (anemia) and overactive thyroid (hyperthyroidism) — can increase pulse pressure as well.

Treating high blood pressure usually reduces pulse pressure as well.


I SEE :)

I wonder what the evidence to support this is? as no-one ever mentions it (does not mean it is not true if no one ever mentions it of course), I for one NEVER EVER heard of it, I knew of MAP (mean arterial pressure) and its relevance



I suggest the two are intertwined.

Being silly, I put each term into PubMed and got the following numbers of hits:

MAP - 23,559

Pulse pressure - 5,507

So BOTH are clearly widely referred to. :-)


eek! Thanks for the info Rod. Ive just taken a random sheet out of my Dr P diaries and worked out all the pulse pressures. Some days my bp was 108/71 and this felt very noticeable and i note my pulse was 112 on this day :-/ . My bps on average on other days were 124/65 with varying pulse rates and my temps were all low. The pulse pressures ranged from 37-64

I will keep a close eye on this...thank you

Do you think a gp will know this stuff or will i have to educate her again??


I wish I had any idea! As it is in the more classically standard areas of medicine, maybe she will? But if not, it is easy to find quite a number of very straight-laced references including on NHS sites.

Try a Google search using:

"pulse pressure"

That comes up, among many others, with this intriguing news-item:

All the best



Hi It is actually perfect if not swinging. 60 to 80 heart rate ideal. Blood pressure ideal too.Both vary a little with age.



The more I reduced levo the better I became. I was plagued with palpitations and tachycardia. It was hell. Pulse shooting up at all times during day for no reason. Highest I registered was 140 bpm. It was at its worst during night, ECG's, trips in ambulances - heart pronounced fine, insomnia etc. No palpitations for ages now and am well.


mmmm...i shall bear this in mind....thank you xx


Some people taking T4 containing medications may be making too much RT3 without realizing. So the more you increase.......the more you block receptors and become increasingly hypo. When extremely hypo the heart doesn't contract (pump) forcefully, so to compensate the heart beats faster. This was what happened in my experience.


hi...yes this makes sense too..thank you xx


I was and still am having similar heart rate issues as you and was taken off of my T3 by GP. Had 24hr monitor which shown up a problem so GP first reduced my T4 then took away my T3.

Went to see an endo last week (sent to him by anesthetist due to pending operation) and he has now done loads of tests from adrenal to coeliac and everything in between. He seems to think that it is not my thyroid conditions that is causing the ongoing problems (feeling tired, weight gain - you know, all the classic thyroid symptoms) but something else such as low VitD AGAIN. If my VitD is low I will be asking him to look more closely as my Parathryoid as, after mega vitD intake last year my levels went from 12.8 to 154 so I'll be wanting to know why and how its dropped again. I will also be asking him to look at my B12 closely as at 320 I think its too low, which he agreed with but my GP refuses to do anything about. He has done all the tests that my GP should have been doing over the last few years (which I know from my time spent on this site is unusual as endo's aren't usually that thorough) but refused due to money issues. If she had done these test I dont think I would ever have needed T3 as, like the endo, I think there are other issues at play here so maybe you need to look more closely at other things. I am also looking at the filler element of thyroid drugs and will be asking him for a purifued option.

My heart issues are still ongoing, even though I am off of the T3 and am now being sent for an echo of my heart.

Hope you find your answers soon and well done for finally getting back to work.

Moggie x


Hi Moggie

It may be low vit last result was 38 last year and ive been supplementing. Ive been for a repeat today of all my bloods but what a performance ive had. I asked i the nurse to check the blood forms to ensure i wouldnt need a second bleed and she argued with me that vit d would be included in my bone profile??? I said it needs a separate request, refused to ring the gp to ask and said " im sure a gp knows how to request the right test" I couldnt be bothered to get into that little chestnut so ive asked the receptionist to check with the gp. How very annoying ! She was only bothered about the surgerys new computer system that was being installed....yeah dont you worry about me....ill pop back for another stabbing!! grrrrrr

Thanks for your comments x x x


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