Blood Pressure increases after 20 years on stabilised thyroxine

I am 58 and have been stabilised on Oroxine ( sodium thyroxine) 150 micrograms daily for about 20 years. My TSH levels have consistently been <0.05 mU/L ( normal range is 0.2-4.0) and free T4 was 17 pmol/L (15-30) with free T3 between 3.9-4.4 pmol. Last week I went to my GP because I was feeling dizzy, havng headaches, nausea and could not tolerate exercise too well. Blood tests showed my TSH the same i.e. below detection levels but free T4 had risen to 19 pmol and bizarrely the normal range had changed to ( 10-20) but I think the lab may have stuffed up! Maybe T4 normal range changes with age- Does anybody know? Free T3 had also risen to 5.1 but that normal range had remained constant at (2.8-6.8). Anyway - my question is - WHAT TO DO ABOUT THE RISE IN BLOOD PRESSURE? I'm 47 kg and exercise almost every day - I do spin 4-5 times per week plus weights and I'm a vegetarian so im fit for my age. This has come as a suprise my some prelim research shows that my kidneys or adrenals could be affected and releasing noradrenaline or angiotensin. can anybody comment?

19 Replies

  • I have always read that raised blood pressure is a symptom rather than a condition. How are your levels of Ferritin - Folate - B12 - VitD ? I notice you are vegetarian so that could have some influence on your B12/Ferritin levels. Although I expect you are supplementing.

    Have you read any of Dr Kendricks blogs on his website ? He has covered blood pressure - saying they kept lowering the acceptable levels in order to treat more people. A bit like Cholesterol !

    Low magnesium is common in most people and can prevent the the arteries from expanding and relaxing with ease. If your Iron is low then the oxygen levels will be lower - and so the heart beats faster to circulate more oxygen. Oxygen adheres to iron in the red blood cells for transportation around the body.

    Am not a medic - just a Hashi's gal with a B12 issue :-)

  • Yes I agree. Thanks for Dr Kendricks article - its quite reassuring. I suspect its a symptom of incorrect thyroxine dosage because apparently Hashimoto sufferers can change spontaneously to different levels of thyroid insufficiency and have their thuroxine dose decreased or increased to suit. Also I'm sure that you are familiar with STTM site who state that BP problems will eventually become inevitable with thyroid issues. My Ferritin is 38 ug/L (normal range is 20-290), Iron Stores 14 ( 10-33) so on lower end of normal, TIBC is 59 ( normal) and iron saturation is 24%. I have started myself on Fe supplement about 10 days ago but my GP told me to stop- she said it was a poison! However, I think I will stick with it for a 30 days. Hb is 122 ( 115-160) so again lower end but still inside normal range. I have been on Mg supplement for about a year so its not Mg insufficiency. My kidney GFR appears excellent so I dont think its a renal artery constriction - but who knows! I'll ask for a B12 test on Friday when I go to GP.

  • Yes, do stay on the Fe supplement, your doctor is talking rot! But, do take 1000 mg vit C with it, to help absorption, and make it easier on your tummy. Your ferritin is awfully low.

  • Your GP is scare-mongering about your iron supplementing. Yes, iron is poisonous, but only if you supplement too much for too long. I had low ferritin, serum iron etc and it took me nearly 2 years to get my ferritin up to mid-range. Other people manage to improve their levels sufficiently in three months. It really depends on your ability to absorb the stuff. Regular testing is absolutely essential.

    The only way of being sure of when to stop is to test regularly. Are you in the UK or elsewhere? I suspect you aren't in the UK, you've had too many sensible blood tests, e.g. the Free T3 and the full iron status check. It is possible to get blood tests done privately without requiring the permission of a doctor in some countries. If you tell us which country you live in, we may be able to point you in the right direction.

    When my iron was very low my blood pressure increased a lot, and I also developed tachycardia (very fast heart rate). As my iron/ferritin levels increased my heart problems and chest pain diminished and diminished. My heart is a lot happier now.

  • I'm in Australia although this all started when I was still in UK earlier this year. I also suspected something was wrong when I couldn't catch my breath and started hyperventilating to get the Oxygen in. Your comments about Ferretin are extremely valuable, thank you I'll stick with it. I chose one with Bit C to help adsorption. Wow, I get chest pain too but I just thought I'd pulled a muscle at tennis!! I suspected mild anaemia as I've been vegetarian for around 20 years. Sounds like in need Fe and maybe B12

  • If you want to get private testing done in Australia, see the relevant link on this page :

    How much iron (and what kind of iron) does the supplement you are taking contain? Many iron supplements contain just enough to give people the normal daily requirement. But if you want to raise iron levels rather than just maintain them, then you need a decent level of iron in your supplement.

  • maggiesloper - if you are supplementing B12 - testing is of little or no vlaue. The results will be skewed and you run the risk of a GP telling you you do not need it - WRONG !!

  • I'm not supplementing with B12. Perhaps I should. What does it do?

  • It could be that you need to increase your thyroid medication - taking your basal temperature is a good indicator of your thyroid state.

    High blood pressure (hypertension) is another disorder associated with hypothyroidism, which causes a reduction of blood flow to one or both kidneys leading to the raised blood pressure. The lower the blood flow, the higher the elevation in blood pressure. Dr. Barnes believed that decreased blood flow to the kidneys, due to hypothyroidism, was the underlying cause of most high blood pressure. Eighty percent of the people entering his study group with a prior diagnosis of high blood pressure had their pressures normalize with thyroid therapy alone.

    If high blood pressure is present, along with a lower than normal basal body temperature, the blood pressure will almost always come down with thyroid hormone therapy alone. When this type of high blood pressure is treated with anti-hypertensive medications alone (without thyroid hormones) the blood pressure does not come down, and the doctor brands this patient as having "refractive hypertension." That term only means that the high blood pressure is refractive (resistant) to the treatment which doctors know to prescribe.

  • Interesting. I thought the reverse I.e. lower the dose to reduce heart rate and BP. However the lowered renal blood flow theory makes sense due to activating peripheral vasoconstriction to attempt to increase core blood flow

  • If you are not sure about the dose of thyroid medication then taking your basal temperature is a good indicator - if your basal temperature is low then you may need to increase.

  • Extremely interesting. Do you have any references in the literature on this topic? I'd like to find out more. Thank you

  • Sorry, but I can't find the references, but here is some info:

    The Basal (at rest) Temperature Test was first described by Dr Broda Barnes in 1942 in The Journal of the American Medical Association. He had noted that, when screening patients prior to testing them for the Basal Metabolic Rate (BMR), their temperatures were consistently lower when the results of the test showed the lowered metabolism of hypothyroidism. The BMR test involves the resting patient having their oxygen consumption and heat output being carefully measured over a time interval. It became clear that the relationship between low BMR and low body temperature was so consistent, that the temperature under basal conditions alone was sufficient to make the diagnosis.

    This test can be valuable in the diagnosis of thyroid problems. It should be used as part of an overall appraisal, where the history of the illness and symptoms are considered as a whole. Where thyroid blood tests are normal, the basal temperature may point clearly to the true diagnosis as there are few causes other than hypothyroidism which produce a consistent low basal temperature. These include malnutrition (or crash dieting), alcoholism and liver failure.

    To do a basal temperature test, it should be done as soon as you wake up and before you get out of bed. In women who are menstruating, their body temperature varies with the cycle; creating errors which can be avoided if the basal temperature is taken on days 2, 3, 4 and 5 of the cycle.

    It doesn't really matter which kind of thermometer you use when doing the basal temperature test, although it is important to be consistent in how you do it.

    1) Note the reading, and do it for several mornings so the results can be averaged out, since they may vary slightly day by day.

    2) If you have taken your temperature under the tongue, the normal temperature is 36.5ºC to 37.2ºC (97.7ºF to 99.0ºF)

    If your temperature is below 36.5ºC (97.7ºF), hypothyroidism/thyroid hormone resistance should be considered if symptoms are present.

    If your temperature is above 37.4ºC (99.2ºF), hyperthyroidism is possible if symptoms are present and if there is no other illness present to cause a fever.

    This test is a guide only as some temperature variations could be due to infection, virus, etc. This test should be used in conjunction with the signs and symptoms.

  • We have a tendency to think that everything wrong with us is due to our thyroids. But of course lots of over 50s have raised blood pressure and I do wonder if it could be totally unrelated. I think in your situation I would certainly keep an open mind about the cause, and not focus too much on the thyroid. If you have been well on the medication a relatively small rise in levels is not a cause for concern normally. Most of the people on here are complaining of being symptomatic, or their doctors are having kittens because of a low TSH.

    Sadly healthy lifestyle is no guarantee - you are less likely to be ill, but its all a matter of statistics, and someone has to be unlucky.

    You haven't actually said what your blood pressure is.

  • Thanks very interesting. My BP has always been around 120/80. It was risen to 140 or 144/85

  • Well, that's an obvious rise, but is it enough to cause all those symptoms by itself? I used to be 120/70 but now 140/80 on a stressed day. But no symptoms.

    How about meditating?

  • I'm not stressed, in fact the opposite! I'm sure it's something else... dose, Fe, b12. Possibly the vasoconstrictive effects of a low heartbeat rate

  • Even if you aren't stressed meditation has been shown to help lower blood pressure.

    Your thyroid levels aren't high enough to raise blood pressure, they would need to be well over range. So I doubt that its thyroid related.

  • Thanks for your comments and insights. Well here some news! It WAS my thyroid medication. I returned to my doctor after stopping all meds completely for 4 days to quickly get blood thyroxine levels down ( had to be drastic as stopping because thyroxine has half life on one month so relatively slow to be metabolised) followed by 25ug daily for another 4 days. My dizzy spells have virtually gone, nausea gone & heart rate slowed down and best of all my BP has fallen back to normal!! Getting more bloods done to confirm but can't really tell until end of month. My doctor said its not unusual for Hashimoto's disease where amount of thyroxine required can go up or down. Sometimes dose required drops as we age due to fall in muscle mass. So overall good results! Now just got to titrate to find my optimum dose

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