Thyroid or menopause? The signs that actually tell them apart

What you will understand

You feel cold when nobody else does. You put a cardigan back on in June, you sleep in socks, and in meetings you are the one who asks whether the window can be closed. Around you, people tell you that you feel the cold, that this is just how you are. Meanwhile, tiredness is not repaired by sleep, weight goes up without the plate having changed, and mood does whatever it likes. You were told it was menopause. Maybe. But there is another explanation, which gives exactly the same symptoms, which mainly affects women, which becomes far more frequent after fifty, and which shows up on a simple blood test. With one thing that is almost never said: even when it is found, treating it will not necessarily make you feel better.

The two pictures resemble each other to the point of merging: persistent fatigue, weight gain with no change in diet, up and down mood, disturbed sleep, dry skin, hair falling out, difficulty concentrating, irregular cycles. That list describes a perimenopause just as well as a thyroid running in slow motion, and none of these symptoms allows you to decide. None. So the confusion runs both ways: women who treat a menopause when their thyroid is responsible, and women put on thyroid hormone when their problem was elsewhere. Both errors cost time, sometimes years. There is even a third case, the one least talked about: both at once. Nothing stops a woman of fifty-two from having a perimenopause and a thyroid that is slowing down. When that is the case, treating one leaves the other untouched, and people conclude too quickly that the treatment does not work, when it was tackling only half of the problem.

Now the figures, with their denominator, because they are often badly quoted. The large American reference survey measured the thyroid of more than seventeen thousand people: hypothyroidism in 4.6% of the population, of which 0.3% overt and 4.3% of the so called subclinical form, that is to say biological and discreet (PMID 11836274). These two numbers deserve to be remembered separately, because almost the whole debate lies in the gap between them. Another finding from the same survey: antithyroid antibodies, markers of an autoimmune process, were present in 11% of the people tested, clearly more often in women, and more and more often with age. That is the heart of the problem: the most frequent cause of hypothyroidism in our countries is an autoimmune disease, which affects women massively and whose frequency increases with age. In other words, the period of life when your thyroid is most likely to falter is exactly the one when your sex hormones go off track. This is not a coincidence of the calendar, it is an overlap. And when two things happen at the same time, we have a very strong tendency to keep only one of them, the expected one. At fifty, the expected one is menopause.

The question is settled by a blood test, and only by a blood test. The first test is TSH. It is not a thyroid hormone: it is the message the brain sends to the thyroid to ask it to work. So the reasoning is the reverse of what you would imagine: if the thyroid produces too little, the brain insists, it shouts louder, and TSH goes up. A high TSH means a thyroid working in slow motion. Depending on the result, free T4 is added, the hormone itself, and sometimes a search for antibodies. That is all: no systematic imaging, no complicated workup. Two practical points: there is no need to fast and the moment in the cycle does not matter; on the other hand, if you already take a thyroid treatment or biotin, that vitamin sold for hair and nails, tell the laboratory, because biotin can distort the measurement in certain analyzers and give a result that looks like hyperthyroidism when everything is fine. Some signs, on the other hand, do genuinely point to the thyroid rather than to menopause: feeling cold (menopause tends to give hot flashes, hypothyroidism makes you cold, it is almost the opposite), constipation that settles in, very dry skin and brittle hair, a general slowing down in the voice, the movements and the thinking, a puffy face especially in the morning around the eyelids, a slower heart rate, and sometimes a goiter.

Then comes the part that almost nobody tells, and which is the real reason for this video. Picture a workup that comes back with a slightly high TSH and a normal T4: the subclinical form, the one that concerns 4.3% of people. You are offered levothyroxine, the replacement hormone. You take it, you wait to feel better, and very often nothing happens. It is neither in your head, nor a personal failure: it is what the trials show. A review published in JAMA in 2018 brought together twenty-one randomized trials, more than two thousand adults. The treatment did bring TSH back into the normal range, but on quality of life, no benefit, and on the symptoms attributed to the thyroid, no benefit either (PMID 30285179). This is not an isolated result: the largest trial on the subject, published in the New England Journal of Medicine, followed more than seven hundred older people with subclinical hypothyroidism, randomly assigned between levothyroxine and placebo. After one year, TSH had indeed fallen in the treated group, but the hypothyroid symptom score was identical, the tiredness score identical, and no benefit appeared on the secondary outcomes (PMID 28402245). The nuance is crucial: these results concern the subclinical form, with a moderately raised TSH. They say nothing about overt hypothyroidism, the one where T4 is low. That one is treated, and the treatment really does change a life. These are two different situations, and they are confused all the time.

Two traps then open up for those in the first case. The first is to increase the doses hoping that it will end up working, when too much thyroid hormone is not neutral and has consequences for the heart and for bone. The second, more insidious, is to stop looking: because an explanation has been found, you stop wondering whether the real cause of the tiredness was not elsewhere, in sleep broken by night sweats, in periods so heavy that they drain the iron stores, or in a perimenopause quite simply. The recommendations of the learned societies are in fact more nuanced than people think: they do not say to treat everyone, they call for taking into account the exact level of TSH, age, the presence of antibodies, symptoms and the cardiovascular context. In a young person, with a clearly raised TSH and positive antibodies, a trial of treatment is genuinely worth discussing; in a person of seventy-five with a TSH barely above the limit, the expected benefit is very small and the risk of overdosing very real. The video also says a word about the other side of the problem, hyperthyroidism, whose discreet form, with a low TSH and normal hormones, increases the risk of atrial fibrillation and speeds up bone loss, which counts doubly after menopause. It finally warns against iodine supplements and products sold as thyroid supports, and it never suggests changing or stopping a treatment: it gives three questions to ask the doctor who follows you.

The key points to remember

• No symptom lets you decide between thyroid and menopause: fatigue, weight gain, up and down mood, sleep, dry skin, hair loss and concentration belong to both pictures. Only the blood test settles it, and it starts with TSH.
• TSH is not a thyroid hormone: it is the message the brain sends to the gland. If the thyroid produces too little, the brain insists and TSH goes up. A high TSH therefore signals a thyroid in slow motion.
• American reference survey, more than seventeen thousand people: hypothyroidism in 4.6% of the population, of which 0.3% overt and 4.3% subclinical; antithyroid antibodies in 11% of the people tested, more often in women and with age (PMID 11836274).
• Four signs genuinely point to the thyroid rather than to menopause: feeling cold, constipation, very dry skin, a general slowing down. To these are added a puffy face in the morning, a slower heart rate and sometimes a goiter.
• Overt hypothyroidism (low T4) and subclinical hypothyroidism (moderately raised TSH, normal T4) are not the same thing. The overt form is treated and the treatment really does change a life. For the subclinical form, twenty-one randomized trials in more than two thousand adults show no benefit on quality of life or on symptoms (PMID 30285179), and the largest trial, in more than seven hundred older people, finds a symptom score and a tiredness score identical to placebo at one year (PMID 28402245).
• Two traps await when treating a subclinical form changes nothing: increasing the doses, when too much thyroid hormone has consequences for the heart and for bone, and giving up looking elsewhere. Finding something does not mean the cause has been found.
• Subclinical hyperthyroidism, with a low TSH and normal hormones, is not a laboratory abnormality without consequences: it increases the risk of atrial fibrillation and speeds up bone loss, which counts doubly after menopause.

Video chapters

1. 0:00 You feel cold when nobody else does
2. 0:44 Two pictures that merge (and sometimes coexist)
3. 1:54 The figures, with their denominator
4. 2:40 Why the thyroid falters at that particular moment
5. 3:26 How the question is settled: T S H, free T 4, antibodies
6. 4:38 The signs that genuinely point to the thyroid
7. 5:22 Subclinical form: what the trials show
8. 6:36 Overt or subclinical: the nuance that changes everything
9. 8:02 Treating or not: a trade-off, not a tick box
10. 8:45 The other side: discreet hyperthyroidism
11. 9:30 Your three questions for the doctor
12. 10:33 Iodine and thyroid supports: caution
13. 11:17 Recap

The scientific sources cited

Every claim in this video rests on a verified reference. Here is the complete list, with the PubMed links.

• Hollowell JG, Staehling NW, Flanders WD, et al. Serum TSH, T4, and thyroid antibodies in the United States population (1988 to 1994): NHANES III. Journal of Clinical Endocrinology & Metabolism. 2002. PMID :. PubMed 11836274
• Feller M, et al. Association of Thyroid Hormone Therapy With Quality of Life and Thyroid-Related Symptoms in Patients With Subclinical Hypothyroidism: A Systematic Review and Meta-analysis. JAMA 2018. PubMed 30285179
• Stott DJ, et al. Thyroid Hormone Therapy for Older Adults with Subclinical Hypothyroidism. N Engl J Med 2017. PubMed 28402245
• Jonklaas J, et al. Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacement. Thyroid 2014. PubMed 25266247
• Villar HC, et al. Thyroid hormone replacement for subclinical hypothyroidism. Cochrane Database Syst Rev 2007. PubMed 17636722
• Inoue K, et al. Association of Subclinical Hypothyroidism and Cardiovascular Disease With Mortality. JAMA Netw Open 2020. PubMed 32031647
• Urgatz B, et al. Subclinical hypothyroidism, outcomes and management guidelines: a narrative review and update of recent literature. Curr Med Res Opin 2023. PubMed 36632720
• Caturegli P, et al. Hashimoto thyroiditis: clinical and diagnostic criteria. Autoimmun Rev 2014. PubMed 24434360
• Palmeiro C, et al. Subclinical hyperthyroidism and cardiovascular risk: recommendations for treatment. Cardiol Rev 2013. PubMed 23563523

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