More evidence that ‘normal’ thyroid function tests do not necessarily mean that all is well with the thyroid and health

Earlier this month, one of my blogs focused on thyroid function testing. The main point I wanted to make was that ‘normal’ thyroid function tests do not necessarily mean all is well with the thyroid and health. The blog focused on research that shows that even with the ‘normal’ range, higher levels of the hormone known as thyroid stimulating hormone (raised levels of which generally mean low thyroid function) are associated with increased body weight.

This week saw the publication of a study in a similar vein [1]. In this case, the researchers involved in this study were looking at the relationship between TSH (also known as thyrotropin) levels and risk of death due to a heart-related condition (heart attack being the main cause here).

Again, this study focused on TSH levels in the ‘normal’ range, which the researchers cite as 0.5-3.5 mlU/L. This is interesting in itself, as the lab I usually use for these tests quotes and upper limit of TSH of 4.20, and I saw a patient yesterday who came with some blood test results where the upper limit of TSH was quoted as 5.50! it seems there is a lack of consensus about what the normal range of TSH should be�

Anyway, focusing back on the study, the research looked at the risk of cardiac death in a group of about 17,000 women and 8000 men over a period of something more than 8 years.

They found no significant relationship between TSH levels and cardiac death risk in men. However, in women, it was a different story. Compared to women with a TSH level of 0.5-1.4 (relatively low levels which should mean relatively high thyroid function):

Women with a TSH level of between 1.5-2.4 were found to be at a 41 per cent increased risk of cardiac death.

Women with a TSH level of between 2.5-3.5 were found to be at a 69 per cent increased risk of cardiac death.

Here again, it seems a study has found that ‘normal’ but perhaps somewhat impaired thyroid function is associated with negative consequences for health.

Managing thyroid issues can be tricky, but I do think there is a case for treating some people with ‘normal’ biochemistry if their clinical picture suggests low thyroid function. Biochemical testing can be important, but at least as important, in my humble opinion, is to make treatment decisions on what a doctor sees and hears in front of him or her.

Quite a few doctors I know express concern at the thought of someone with ‘normal’ test results taking thyroid hormone. They often cite the risk of treatment, including risks to the heart. Obviously, I think it’s a good thing that as doctors we should be aware of the risks associated with thyroid hormone treatment. I just wish more doctors would see the other side: that there can be considerable risks associated with not treating too.


1. Asvold BO, et al. Thyrotropin Levels and Risk of Fatal Coronary Heart Disease: The HUNT Study. Arch Intern Med. 2008;168(8):855-860

21 Responses to More evidence that ‘normal’ thyroid function tests do not necessarily mean that all is well with the thyroid and health

  1. Amy Dungan 1 May 2008 at 8:27 pm #

    Thank you so much for your posts on thyroid Dr. Briffa. I believe I’m one of those who have been misdiagnosed. A few years ago I was struggling with keeping my weight stabilized and extreme fatigue. I suspected a thyroid problem and went to my doctor. She tested me and found my TSH to be 3.5. She saw no need for concern, although I had recently read that what was considered “normal” had changed and anything over 3 should be considered suspect. I asked to be referred to a endo, which she did. The endo tested me and found my TSH to be 3.3. She also saw no need for concern despite many of my symptoms lining up with thyroid issues. She waved me off with a prescription for antidepressants and exercise. I was so upset because I felt she wasn’t taking me seriously.
    I’ve since just dealt with it the best I could… and gained back almost 70 lbs. Some of the gain was certainly my fault because I eventually quit following a healthy diet. But now that I’m following said diet again, I am struggling to get the excess weight off and keep it off. I am still exhausted most of the time and my hair seems to be coming out more than I think is normal. My dad was diagnosed with thyroid problems recently and I’m considering going to his doctor to have mine checked. You have helped me make up my mind to try once again to get help.

  2. Hilda 2 May 2008 at 12:05 pm #

    Amy, There are other doctors that you can see for a second opinion. Dr Briffa being one of them. There are also lots of books you can read regarding helping the thyroid naturally. A naturopath or nutritionist can give supplements which can support the thyroid.

    However I agree with you as I am in the same position myself. My TSH is even higher than yours but I do inderstand why my GP wont give me thyroxine. It is for life and your own gland can stop producing it if is taken. So I am in a quandry as to what to do. However the study above is worrying.

  3. Hilda 3 May 2008 at 3:14 pm #

    Tina, Could you please give me your email address. I couldn’t find it on the website. Regards Hilda

  4. Anna 3 May 2008 at 6:07 pm #

    The worst part of this is it just too often very difficult to get not only a proper diagnosis for low thyroid function, but even with a diagnosis, it is very difficult to get proper treatment that not only gets the lab results back in line, but also helps the patient to feel better. Too many doctors simply leave the patient “high and dry” because they simply prescribe synthetic T4, get the lab result to a range they like, but still leave the patient not feeling well enough. If the patient still feels unwell, out comes the antidepressant samples or Rx pad.

    Conventional medical wisdom since the 70s says that hypothyroidism is no longer common (due to iodized salt, but now many avoid salt), and that it is easy to detect and treat using the 3rd generation TSH test (considered to be the Gold Standard). Not enough doctors also test for free T4 and T3 levels (free hormone, not protein-bound), as well as thyroid anti-bodies). Additionally, many thyroid glands make enough T4 (the inactive hormone) but there is inefficient conversion to the active T3 hormone at the tissue (cellular) level).

    In reality, many, if not most doctors simply treat the lab test results and not the patient, resulting in many missed diagnoses, improper and/or under treatment, and continued patient suffering. There is a reason endocrinologists are called ” the accountants of medicine”. Often, you aren’t a patient, you are lab numbers. I’ve been to an endocrinologist who rarely looked at me, but spent most of the appt looking at the lab reports.

    Additionally, there is a lot of misinformation that has been taught to doctors, especially primary care doctors, that makes them reluctant to prescribe enough thyroid hormone replacement to get the patient feeling better (they believe it will cause osteoporosis). Additionally, the conventional treatment of hypothyroidism often requires customized treatment for each patient, but the doses in conventional thyroid preparations are too often not optimal (especially with T3). Very few doctors have experience with compounded Rx anymore, but that sort of individual treatment is invaluable for thyroid patients. Most of the time they just prescribe the best selling synthetic T4 drug, because that is the one pushed by a drug rep.

    I know this firsthand, as I am hypothyroid. I had classic and increasing symptoms for more than a decade, multiple TSH tests (but my lab used the controversial conventional “normal” reference range of .5-5.5mIU/L). My labs were gradually increasing over the years and always had been in the “suspicious end”). My primary care doctor considered herself somewhat of an expert on the thyroid, yet she insisted my thyroid function was fine (yet even her nurse always joked about how abnormally low my temp always was). But she was happy to Rx any number of other medications for the symptoms. No thanks. When I finally learned about thyroid function on my own, I realized that I hadn’t been getting good care at all for a decade.

    I saw two more primary care doctors, one DO family practitioner in my network and one internist out of my network, who would prescribe thyroid hormone for me, but in too small a dose to be effective (they were terrified of prescribing too much), so when my TSH got to a number they liked, but many of the symptoms still remained (especially fatigue, that instead of all the time, hit like a brick in the afternoon) they wanted to prescribe anti-depressants. No thanks.

    Finally I just went outside my network (out of state even) to a recommended doctor with a practice only in thyroid disorders and found appropriate treatment (T4 with compounded natural thyroid extract for a treatment ratio of 98% T4 to 2% T3 – adjusted seasonally for winter and summer). It was worth every bit of out-of-pocket costs and travel inconvenience because two years later, life is nearly normal now, without taking additional Rx to suppress hypothyroid symptoms.

    I really hope this latest study opens the eyes of many doctors, because there is a lot at stake with low thyroid function beyond fatal heart disease. Undiagnosed hypothyroidism has a profound effect on fertility; enthusiasm and energy to pursue work, leisure, and personal interests; mood and mental well-being, as well as ability to concentrate and think critically; physiological body functions; and of course, overall health and well-being for the long term. It’s important to keep in mind the thyroid gland makes “the master hormone”, like a conductor, which in turn orchestrates many of the other hormone levels as well as sets the pace for the entire body. When thyroid function is even a little bit off, every single cell in the body has trouble functioning “in harmony”.

  5. Carol Homer 4 May 2008 at 9:32 pm #


    lovely to hear all your comments. Life with hypothyroidism is certainly tough, especially when brain fog seems almost permanent and the ability to ‘insist’ on being taken seriously fades more each day. I thought I was lucky when I was given thyroxine, BUT symptoms persist and now I am concerned about my heart – oh heck, any advice on next step would be most useful.

  6. Anna 4 May 2008 at 10:59 pm #

    Carol, you might consider getting your vit D level checked, too.

  7. Julie White 14 May 2008 at 4:29 pm #

    Carol and all

    I thought my life would change when I was finally prescribed Thyroxine, but, like you, found that after the initial 3 week happy honeymoon my symptoms returned with a vengence. My doctor told me it might mean there was something else wrong with me and wanted to do more tests. I didnt give her the chance and took things into my own hands. I read “The Great Thyroid Scandal and How to Survive it” by Dr Barry Durrant-Peatfield. It was brilliant. I now have a very good understanding of the issues and science associated with impaired thyroid function and, armed with this knowledge took myself to a private doctor who would prescribe “Armour Thyroid” which is the natural version of thyroxine and the forerunner in this country up until the 1960s. I also identified that I had “low Adrenal Function” which impairs the body’s processing of thyroid hormones. I started taking “Adrenal glandular suppliment which made the Armour start to work. I have felt much better. I lost 2 1/2 stone following a very low carb diet and feel like my old self again. I am deeply frustrated to hear about how the NHS continues to let this huge section of the population down. They are simply ignoring a growing health problem which can lead to misery and early death for a massive section of the population.

  8. Claire 16 May 2008 at 4:23 pm #

    Hello all

    I’m again one of many other people with the “your TSH is normal (2.8) so shut up and go home” situation and the doctor doesn’t want to refer me to an endocrinologist as I’m not interresting anough for the NHS to take me serious. I’ve been suffering with the mentioned symptoms for over 10 years now and been diagnosed with Fibromyalgia/ME and all kinds of simular illnesses. I’m just so fed up with hearing ” you just have to live with it and rest a lot” more then 10 hours a day(I think by myself)?

    I have done a lot of research on this and really believe that I have an underactive thyroid and would benefit from treatment. I’ve been to numerous doctors with this and keep hearing the same thing. Could anyone (Julie, Tina and others who finally fo )please tell me which private doctors will treat you because I havn’t found anyone yet (Kent).

    Can anyone give me some tips please?

  9. Tina Michelucci 12 July 2008 at 12:15 am #

    Hi Claire
    Dr Andrew Wright in Bolton is very good – not near to you sadly!

  10. Linda Thipthorp 20 September 2008 at 6:41 pm #


    I too have suffered from birth with thyroid problems but little did I know at that young age what was to come. I was born with a lingual thyroid (the gland was embedded in the tongue)and all through my life I suffered with hypothyroidism. I too had test after test but they all came back “within normal range”. Many doctors, (most not their fault) have become technocrats and do not look at the patient anymore they seem to have been taught not to do this. I was showing extreme signs of hypothyroidism with dreadful fatigue and a very low immune system. I had infection after infection. I have had most organs removed now through being undiagnosed and mistreated and eventually underwent a horrendous operation in London to remove the lingual thyroid from my tongue. After this I was again guided by these blood tests. T4 was given and I eventually fell into a myxodema coma. I lay in bed for 18 months with fibromyalgia, ME and CFS. Brain fog and everything else you can think of until I found out about Dr Peatfield. It’s a long story so I will cut it short. I recovered, now ski, run and go to work but it took a long time to come back from near death. I run a helpline now as I feel my experience has given me so much to give others. The adrenal glands are also ignored and due to the fact that cortisol has to be present to convert T4 to T3 (the active hormone) to enter the cells in the body it is no wonder most people do not get well. It is a very fine balance to get these two hormones balanced and the longer patients are left the more likely they are to be suffering with adrenal problems as well as thyroid problems. My story is in Dr Peatfields book “The Great Thyroid Scandal and How to Survive it”. I will continue to help others and continue to try to get this system changed. Blood tests do not work and are the main cause of our hospitals spilling over with sick patients. It is no good throwing drugs at a patient, you have to get to the cause of the problem, ie a low metabolism. The great Broda Barnes was right when he said, the pulse before rising is a better indication of a slow metabolism that any blood test. Linda Thipthorp, Metabolic Advisor

  11. Mimi Blanksby 20 September 2008 at 6:55 pm #

    Very interested to read posts about private treatment from Julie and the additional supplement. I was diagnosed with underactive thyroid only after I had gained 3-4 stone. Ihave been taing Thyroxine ever since and only lose weight when I am pregnant (?!). Interested to hear of any private doctors in Bucks/Berks or London I suppose as I would really like to get on with my life….
    Any thoughts and ideas welcome.

  12. Veronica 7 November 2008 at 8:59 pm #

    How familiar. I am a staff nurse and have suffered with both high cholesterol and hypothyroid for 8 years. Finally my doctor gave my thyroxin when my TSH was 10.02 which kept my T4 at 11.2.She would only give me 50mcg however. When I saw a surgeon for something unrelated the first thing he said was “why are you on such a small amount of thyroxin”? For me its familiar as all the women in my family on my mothers side have hypothyroid problems and are on thyroxin. I never felt well on 50 mcg. My resting pulse at night was sometimes as low as 40 and my blood pressure was never about 100/50. Finally this year I confronted my GP as my husband and I were going to Rome for 5 days and I knew I had to walk all day for 4-6 hours at least. She doubled it to 100mcg. At least my pulse has come up and my cholesterol down. It is so obvious that if the body is slow the arteries will clog up and then IHD starts. My T4 is 17 today and my TSH O.O3 which is low. I access my own results at work so my GP doesn’t know them yet. Watch this space.

  13. thyroidguy 14 December 2008 at 12:29 am #

    I totally agree with the author that blood test doesnt mean that everything is good with thyroid. Mostly, if there are any symptoms, then there is obviously something wrong. Trouble is doctors just dont want to listen and people have no choice but to live with the disease for the rest of their life!

  14. chills/cold girl 1 January 2009 at 5:43 am #

    I have had problems with thyroid in past. I am not on medications now. My TSH, 3rd generation was 4.18. The only other tests done were antibiodies. Less than 10.0. I have freezing hands, feet, tired, fatigued, nausea, and currently they are working me up for my gall bladder. I also when I get these cold sensations from my neck to chest, down left arm. It is causing me to panic. I am usually in control so these feelings are awful . I was told by MA that labs normal but PA said borderline. I am getting another test done for my gallbladder done. i still feel I should have further work up for thyroid. What tests? What is normal? I really just want to be me again.

  15. trish 17 January 2009 at 9:14 am #

    hi. my name’s Trish, i am now 45 and have been suffering with nearly all the symtoms for underactive thyroid for at least 20 years but have only been diagnosed in last 5. I am currently on 125mg level of thyroxine. It works enough that i can actually walk over 100 yards now, but nothing else has changed……….i am at my wits end, i feel i have no life, i love to go out on my motorbike but i’m finding it too much to concentrate and the fatigue is rediculous, i feel that life is not worth living because this is no life, it’s just a big struggle……please, please, can anyone help

  16. kristie 11 March 2009 at 5:28 am #

    Hi my name is kristie i am 32 will be 33 this may i too have suffered many years with low to no energy at all crazy amounts of weight gain ,swelling hands ,feet and legs i am always freezing ,my skin is severely dry i have depression, anxiety i always feel in a daze and i have severe constipation and muscle aches but i have always just been told i am a hypercondriac i have had several blood tests done thats always the first thing they want to check but it always comes back fine recently and im wrote off as severly depressed and put on anti depressants recently i was put on diet aid phenteramine and i lost weight extremly well i felt pretty good all was ok until i had to come off them as expected i felt like crap for a while i was told i would then i felt a little better then all of a sudden i felt awful and within 2 months i have gained 20 lbs 10 within the last week so today i went my doctor he suggested a thyroid test i told him it will come back negative it always does i asked him if there was another way to test he said yes but my insurance probaly would buck on having it done im more scared of a negative result than a posativ that may seem strange but you have to understand i just want to know whats wrong with me i cant live this way anymore i know that i have a thyroid problem i know my body and its telling me somthing is wrong but no one will listen to me im so frusterated i want to feel good but i only feel like crap everyday i just graduated beauty school and got my license and want to start a career but feeling this way i dont know if thats even possible i will have the results tomarrow i’m anxious to know

  17. Lily 26 March 2009 at 3:58 pm #

    Ladies, unless there is some reason for staying with the same doctor….move on down the road to someone that practices integrated medicine, keep a journal of your meds, things bothering you that are symptomatic with your emotions and perhaps the foods that you ingest, body temperatures that seem to be sub normal and move on to another physician than actually listens to you. YOU will not hurt the feelings of the physician that you see if you find another person to HELP you. After all it is your body and you are the caseworker that can get something done only when you are able to communicate that you do not want to be treated as a group lab value but as an individual.
    Took me 3 years to find a listener….An endo told me that he did not know of any “disease” that caused dry skin. So after waiting to see this pillar of allopatihic medicine I moved down the road to find one that believed in Armour. Good luck you can do it!!!

  18. liz 28 March 2009 at 7:41 pm #

    Hi to everyone out there with an underactive thyroid! I am at my wits end because my doctor refuses to treat me. My tsh is 5.8 and I am struggling to keep going. My doctor says the upper limit is 6.0. I am a full time primary school teacher as well as a mum am confused and exhausted! Can anyone help or advise please?

  19. Angie Johnson 9 September 2009 at 11:25 pm #

    Hi Linda, Could you please tell me do you still run your helpline, I have underactive thyroid am on thyroxine and feel terrible.
    please could you email me.

    thanks Angie

  20. F.Sidney 24 May 2011 at 9:03 pm #

    My mother suffered from a weak thyroid for years, too.
    I am now studying herbalism and I have found out that instead of tablets and surgery, a system cleanse is more useful. If you have never heard of Dr. Christopher, the most famous herbalist doctor in the 60-70s, this is a good time!
    In his website I have learned so much about what stops our body work and incidentally, glands are included in his site. Happy reading!

  21. Salwa Downey 27 October 2011 at 5:49 pm #

    I think best thing is to change the doctor if you are struggling with your current one. I was on generic thyroxine and my GP wouldnt let me go on Eltroxin. Had to take my research with me to show him how different generics can have different fillers and finally now I take Eltroxin!

    Good Luck to all of you.

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