Influence of cigarette smoking on thyroid gland - an update

Influence of cigarette smoking on thyroid gland - an update

Over many years, the links between smoking and thyroid have proved to be extraordinarily unclear. With the exception of Graves and TED, we have seen all sorts of ideas and supposition but little evidence. One particularly interesting possibility is that smoking is far more intimately linked - and might help to stave off thyroid disorders, or at least somehow mask them, which is why so many people seem to report "giving up" as a the time that they started to suffer.

Endokrynol Pol. 2014;65(1):54-62. doi: 10.5603/EP.2014.0008.

Influence of cigarette smoking on thyroid gland - an update.

Sawicka-Gutaj N1, Gutaj P, Sowiński J, Wender-Ożegowska E, Czarnywojtek A, Brązert J, Ruchała M.


Many studies have shown that cigarette smoking exerts multiple effects on the thyroid gland. Smoking seems to induce changes in thyroid function tests, like decrease in TSH and increase in thyroid hormones. However, these alterations are usually mild. In addition, tobacco smoking may also play a role in thyroid autoimmunity. Many studies have confirmed a significant influence of smoking on Graves' hyperthyroidism and particularly on Graves' orbitopathy. Here, smoking may increase the risk of disease development, may reduce the effectiveness of treatment, and eventually induce relapse. The role of smoking in Hashimoto's thyroiditis is not as well established as in Graves' disease. Nonetheless, lower prevalence of thyroglobulin antibodies, thyroperoxidase antibiodies and hypothyroidism were found in smokers. These findings contrast with a study that reported increased risk of hypothyroidism in smokers with Hashimoto's thyroiditis. Moreover, cigarette smoking increases the incidence of multinodular goitre, especially in iodine-deficient areas. Some studies have examined cigarette smoking in relation to the risk of thyroid cancer. Interestingly, many of them have shown that smoking may reduce the risk of differentiated thyroid cancer. Furthermore, both active and passive smoking during pregnancy might modify maternal and foetal thyroid function. This review evaluates the current data concerning the influence of cigarette smoking on thyroid gland, including hormonal changes, autoimmunity and selected diseases. These findings, however, in our opinion, should be carefully evaluated and some of them are not totally evidence-based. Further studies are required to explain the effects of smoking upon thyroid pathophysiology. (Endokrynol Pol 2014; 65 (1): 54-62).

PMID: 24549603 [PubMed - in process]


Image: Thomas Rowlandson - Taunting with Smoke from a Pipe

Last edited by

31 Replies

  • Hi Rod I read that one, the "reduce the risk of thyroid cancer thing" - so didn't dare post it!

    I prefer to look into what's in the actual tobacco - nicotenic acid (Niacin B3) well apart from nasty additives like cyanide, tar etc. funny how they always say - further studies are required!

    I don't condone smoking - (I just decided to stop on my birthday boxing day) but I would sure like to have a poll to see who's diagnosed HypoT after quitting to make folk aware what to expect - (Docs probably are) I never knew it speeds metabolism and lowers TSH either. Tricky subject, and taboo. J :D

    (meanwhile since stopping I have had Strep throat twice (tonsillitis) Sinus/ear problems and gained another half stone - without eating more! no appetite as still no sense of smell/taste/hunger) not that I'm moaning or anything!

    PS the first time I quit (for 7 years) I gained 4 stone too, trying to think back that far is difficult.

  • It took a while, so maybe it wasn't connected, but I did become hypothyroid after giving up.

    A nightmare trying to tease out causality from the numbers - after all, maybe the people who are prone to thyroid issues are the ones who tend to start smoking and get hooked?

    What is radical is your suggestion that docs are probably aware? Aware of what, I wonder!!!! :-) :-) :-)

  • Quitting smoking triggers hypothyroidism. They'll not want to put people off quitting.

  • yes

  • My doc most definitely was not aware of any link between smoking and thyroid. He just looked at me blankly when I suggested it. He didn't even congratulate me on having given up! Just brushed the whole subject aside and continued to offer me prozac <sigh>

  • No surprise there then, that's the first lecture - the blank look (practised in the mirror) anything I utter I get the blank look (last time was WHAT! a TSH of 4.57 is normal? blank look - ok maybe a slightly raised eyebrow at my tone!)

    They're only happy if you go to the quit smoking clinic, there's actually funding for advice (asking if you know the risks) first, then clinic, saying it's so hard as an addiction, avoided patches & malarky, then checkups.... no funding if you just decide...

    - when will they realise that you'll just do it when you're good and ready and actually want to?

    grr! rant over! I am still learning to take deep (smoke-free) breaths & not let things get to me x

  • "...smoking may reduce the risk of differentiated thyroid cancer."

    Not for me, it didn't:(

    Mary Shomon refers to quitting smoking as a trigger in section 2. Sometimes Patients Know Best

    It's been widely [anecdotally] reported on e-cig and vaping sites for over 3 years.

  • There's a collection of smoking related research papers on this page of the main TUK website:

  • When I was diagnosed with Graves' and displaying the first sign if thyroid eye disease the endo said, ironically you smoking may have actually damped your thyroid but unfortunately that far outweighs the fact that smoking might very well be the reason for your eye disease and if you want to help with a positive outcome you must stop smoking.

    I did stop 6 months later. I went cold turkey. But my eyes have deteriorated more so since stopping. That was 2 and half years ago. In fact I recently had an MRI confirming serious deterioration.

    I wonder if the stress of stopping has influenced the outcome somehow?

  • I stopped smoking last April and was diagnosed with Graves disease in Sept having been unwell for probably 3 months before going to GP. Had I not stopped I wonder!!!!

  • Hi me too I stopped in the January 3 years ago and due to feeling very unwell went to the gp and was also diagnosed with graves. My gp reckoned all that had kept me upright was the fact I had smoked drank buckets of tea and munched chocolate bars. Odd thing is I had been noticing after dental visits that the injection was wearing off within 30 minutes and I daftly thought the NHS was cutting back on the anaesthetic. X

  • Hi I gave up smoking jan 13 and was diagnosed with Graves jan 14.

  • I gave up smoking November 2012...6 months later diagnosed hypothyroidism and have been very ill with many things since ..The last being polymyalgia. ..I've often wondered how things would be if I'd never given up my 20 a day habit ...I'm now overweight ...can hardly walk ..and feel 30 yrs older

  • I've always believed there was a link daughter always says you were healthy until you gave up smoking ...strange but true ....think as someone says ...doctors know but can't put you off ......

  • exactly the same with me, I was diagnosed after stopping smoking, and hubby said you seemed fitter when you smoked! horrible thing is, I did feel fitter!

    still glad I gave up though.:)

  • I have Graves and I stopped smoking eyes were ok been smoking for a month and my eyes felt pressured and are swollen...stopped smoking Monday, not pressured but still swollen... If I have a sneaky cig, family always know.....hope the swelling goes soon.....

  • I can categorically state that my Hashimoto's did not manifest itself until after I stopped smoking! But surely I feel better, right? Now I'm carrying 3 stone extra weight and oh dear... I've developed asthma and nasal polyps too! The only thing that did feel any benefit, quite frankly, was my wallet, but that soon got sorted by the cost of living... I sometimes wish I hadn't bothered.

  • I quit smoking last May 2013 after smoking for 30 years , I was then diagnosed under active in the November 2013, still struggling to get my doseage right but finally my doc has referred me to an endo!!! I'm just praying he is more helpful than my doctor !!

  • In our finalized trial to be published, we found no relationship between the TSH/FT4 or TSH/FT3 relation and smoking habits. And no gender differences. There was a mild relationship between TSH itself and smoking, but TSH was not correlated with FT3 in euthyroid people generally. The problem with most studies is that they are univariate; that is, they compare only one thing with another. In our studies we've done multivariate analysis; that is comparing many things with each other. In this way things that might have a parallel effect with smoking get discovered, and false relationships can be worked out and exposed. There were relationship changes between FT4 or FT3 with age and body mass. I think some of the studies on smoking may confound the real changes taking place like eg people smoking being slimmer in general than nonsmokers.

  • Diogenes, when do you expect the study to be published and in what journal? PR

  • We certainly will not try to publish in US journals - you would be surprised at the dogged refusal to confront the issues, with the reviewers instead trying unscientific dismissive tactics there (I don't like it therefore it isn't true). I think we might try European Journal of Endocrinology first as Rudolf Hoermann's pioneering paper that started this all off was published there in 2010. We're trying to submit I would guess within the next 8 weeks or so. But there is no guarantee of success. Our papers about T4 therapy and the dismissal of the universally held paradigm of there being a constant TSH-FT4 relation over the whole thyroid function spectrum, which now are receiving increasing attention, took many refusals by august US journals and by UK ones as well until we finally succeeded. None of the reviewer's comments in the refusals were either scientific or objective - the lack of intellectual quality made my hair curl (even though I now have little left). Note, there are medical people out there who will go to the stake denying their errors. I've had two careers in science - one bacterial molecular biology and one thyroidal. Reviewing of mol biol papers was always rigorous but fair. I wish I could say that of the thyroid field, in which published and influential garbage litters the discipline. If the garbage was easily buried fair enough. But there are some accepted paradigms in thyroidology that frankly are horsefeathers (as they say over there) and based on crap science.

  • Please be sure and let us all know when it is published. That is one of the few studies I'd actually be willing to buy. PR

  • When and if it gets published I'll try to forward it on. I'll naturally go the admin way so that they can broadcast it.

  • That is interesting. Thank you.

    One of the themes that has come up so often is people getting diagnosed in the months to year or two after giving up smoking. To begin with I dismissed it but the issue has kept cropping up. Maybe it is purely perception (or mis-perception) but I do continue to think that there might be something.

    Do you think that there could be any degree of "masking" of hypothyroid symptoms whilst smoking? Or that people are more likely to give up smoking when they are becoming hypothyroid?

    Maybe the issue only arises in the months around giving up? Would your analysis have been able to identify that?


  • There may be something in it in this sense. Smoking does affect your general health and affects blood flow amongst other longer term matters, like skin changes, lung capacity, nicotine addiction, less interest in food etc. If perhaps some people are leaning slightly towards thyroid dysfunction, but wouldn't have gone "over the edge" if they hadn't smoked, then the smoking could tip them over but hide the symptoms until they stopped. That is, a permanent shift in the TSH balance that longterm smoking somehow counteracts. The effect whatever it is seems relatively mild and of course doesn't affect the majority, but it would be interesting to do a prospective study to find the proportion of nonsmokers and of smokers who do become hypothyroid. This would be an extremely longterm study though. We haven't any data of this kind in our study, merely comparing current smokers against nonsmokers.

  • Thank you.

    Maybe the changes to tobacco use (and, indeed, the widely used vaping devices) will goon to have their own impacts as well!


  • I stopped smoking in June 2012 and was was diagnosed with graves in may 2013, I was feeling wretched by that time and was on beta blockers

  • I stopped smoking and had a miscarriage around the same time when I was 28, Started Putting on weight and feeling exhausted and went on to get more and more Thyroid symptoms but didn't get diagnosed for another 11years by which time I had severe Mixodema. That was 27yrs ago. Ii always thought that maybe the Miscarrage was responsible for my Thyroid problem but in the last few months reading on here maybe my Thyroid was responsible for my miscarriage? But I had stopped smoking a few months before.

  • I definitely think becoming hypo helped me give up smoking. The first symptom I had was really painful thumbs which I put down to lack of exercise of flicking the lighter and the end of the cigarette. As the rest of the family smoked and could not bother to empty ashtrays and leaving empty packs on the side. When the tiredness set in it made it even easier to cope with as I could not lift them either lol. Took over a year later before I was given levo but still cannot be bothered to smoke even nine years later.

  • ELO IV ONLY JUST JOINED AND I FIND THIS VERY INTERESTING . I quite smoking 3 years ago and since then I have a underactive thyroid and put on 3 half-tone I eat very healthy and I can't lose a lb iv bean on leviroxin  for a year they say it is now fine no further action needed . I've never felt so depressed with this weight gaine .iv even thought about shoping them or start smoking again but I can't stand the smell . As anyone ever stopped and if so how was they ,I always had a small neck and now that is swelling to . Can any one give me some advice pleas as I'm new to all this many thanks. 

  • Welcome,

    I suggest that you write your own post/question.

    Buried down here on a two-year old thread, it will not be noticed by many.

    If you have them, post any blood test result you know. (And if you don't know them, ask your GP surgery for them. You are entitled to know what they were.)

    Then you should get more responses.

    What you say about being unable to stand the smell of smoke is common and a surprisingly strong effect.

You may also like...