A Newly Discovered Cause of Women’s Fatigue

Health Tips / A Newly Discovered Cause of Women’s Fatigue

Posted 12/12/2011

Given the number of women who walk around feeling tired all the time, it’s truly unfortunate that the important piece of research we’re discussing today didn’t generate more publicity.

Tucked away in the small-circulation medical journal Thyroid, whose readership is probably limited to endocrinologists specializing in thyroid disorders, there appeared an article about Hashimoto’s thyroiditis that really should have been published in a journal that every doctor reads, like JAMA or American Family Physician.

The autoimmune disorder Hashimoto’s thyroiditis is one of the most frequent causes of low-thyroid (hypothyroidism) conditions.

When you don’t have enough of the essential thyroid hormone, you’ll feel quite an assortment of symptoms, the most common by far being fatigue–a pervasive, 24/7 sense of never having enough energy to do the activities you enjoy. In fact, you may be so fatigued that your muscles actually feel weak.

Beyond fatigue, you may experience weight gain and have an impossible time trying to lose it. You might notice dry skin, dry hair, hair loss, and a peculiar thinning of the outer third of your eyebrows. You may feel mentally sluggish and constantly cold, even on a warm day. In the sack, your partner will shriek that your feet are like cakes of ice (and you really do prefer wearing socks to bed to keep your feet warm).

All this and more if you have low levels of thyroid hormone. You might notice puffiness around your eyes, your usually healthy glow replaced by a pasty complexion. You may be a bit constipated, and your periods have changed too. Having problems getting pregnant? Low thyroid can be involved. In people with severe hypothyroidism, this strange symptom occurs: your tongue actually feels too large for your mouth.

Tests for low thyroid

If you bring any or all of these symptoms to your doctor, any physician with a pulse will order a thyroid profile, a test that measures two thyroid hormones–T3 and T4–as well as a hormone from your pituitary gland that controls your thyroid, called TSH (thyroid-stimulating hormone).

With low thyroid, the T3 and T4 are low, the TSH (as your pituitary struggles valiantly to stimulate the thyroid) is high.

If your TSH is elevated and your T3/T4 low, your doctor might next order a test measuring anti-thyroid antibodies, which determines if Hashimoto’s thyroiditis is the cause of your underactive thyroid. Having your immune system create antibodies against any organ in your body is the very definition of an autoimmune disease. In this case these antibodies are targeting your thyroid—as though it were a sort of alien invader when it’s actually an utterly necessary part of your body.

Autoimmune disorders explained

We don’t know exactly what goes wrong with the immune systems of certain people, overwhelmingly women in a 20-to-1 ratio over men, but Hashimoto’s is one of several such autoimmune disorders, as are lupus, rheumatoid arthritis, and Sjögren’s syndrome.

It’s widely accepted that women’s immune systems are simply different from those of men, because the female immune system must adjust itself to the presence of a “foreign body” when a woman is pregnant.  Since half her embryo’s DNA is from a foreign source (dad), her immune system can’t simply reject this tissue or we’d never as a species be able to reproduce.

This difference in immunity somehow renders women more susceptible to all the autoimmune disorders, and Hashimoto’s thyroiditis is the most common.


When your doctor sees your elevated TSH and your similarly elevated thyroid antibodies, look carefully and you may see a subtle flicker of personal pride flashing across her face—she’s made a diagnosis of Hashimoto’s. She knows the source of your fatigue and that once you’re taking thyroid replacement hormone (Synthroid, Armour thyroid, etc.) you’ll feel better.

Your doctor may need to adjust your dose over time, using your steadily declining TSH as a guideline. As you take your thyroid replacement hormone, your levels of TSH will go down. This is because your pituitary gland no longer must flog your thyroid to get it to produce its hormone. Your smart pituitary recognizes that the thyroid replacement is in your system and is doing its job.

When your TSH is down to a normal level, you’ll be pronounced well and told that you’ll need to remain on a thyroid hormone for the remainder of your current incarnation.

“Sorry! Not quite as simple as that,” proclaimed researchers from the Medical University of Vienna, Austria, in their Thyroid journal article. What they discovered (and this is why the article is so important) is that, in women, the presence of thyroid antibodies themselves–even if you have completely normal levels of T3/T4–can cause symptoms identical to those of low thyroid.

It’s the presence of these antibodies as the newly discovered cause of fatigue that led to today’s health tip title. This is a very important piece of news and leads to a couple of serious possibilities:
• If a woman has all the symptoms of low thyroid but has normal hormone levels and normal TSH, she should not be hearing any doctor say “Your thyroid tests are normal. Whatever’s causing your fatigue, it’s not your thyroid.”

Instead, she should have her thyroid antibodies measured. If they’re elevated, her doctor should seriously consider prescribing thyroid hormone despite her normal hormone levels, using as a gauge to determine the correct dose how she feels (called “clinical response”) rather than hormone level tests. Unfortunately, women seeing their doctors for fatigue will find that virtually no physician routinely measures these antibodies.

• A woman diagnosed with Hashimoto’s thyroiditis whose antibody levels are especially high may need a higher dose of thyroid hormone than usual. And anyone tracking the fluctuations of her TSH as a guide to adjusting her thyroid hormone dose may prescribe an erroneously low dose of thyroid hormone for her particular situation.

A woman with high antibody levels may feel better on such a high dose that her lab test would register “hyperthyroid,” meaning overactive thyroid. In the past, when this occurred, doctors would lower the thyroid dose, but this article suggests “not so fast…”

We’re talking huge numbers of mainly women in this situation. Low thyroid probably affects up to 20% of women as they enter their forties. Of these, half have no access to our health care system, so they simply remain undiagnosed and tired all the time.

For those with insurance, we’ve added another large group of fatigued women: those who have been to their doctors, had their thyroid hormones tested, and were told they were normal. This group should return pronto, this health tip in hand, and say, “Listen, doc, I want you to test my thyroid antibodies. Let me show you this article…”

Be well,
David Edelberg, MD

0 thoughts on “A Newly Discovered Cause of Women’s Fatigue

    Thank you for writing about this – I am one of these women who traveled this road for a long time until I discovered that this is my situation.

    Elizabeth Najda
    Posted December 15, 2011 at 6:17 pm

    This is quite interesting. As you say, one has the impression that the school appropach to the thyroid is quite simplistic. If only the symptoms would be more specific and the treatment responses more convincing! Could you, please, give me the reference of the article you quoted? Thanks.

    Lorenz Fluri
    Posted December 14, 2011 at 10:30 am

    When the pituitary goes into overdrive trying to “flog” the thyroid into normal activity, the adrenal can get “fatigued” in the process. Any chronic stress situation can exhaust the adrenal as well (cf “Adrenal Fatigue: the 21st Century Stress Syndrome by J Williams). The adrenal can be easily tested with a take home kit that measures salivary cortisol levels in one single day

    Dr E
    Posted December 13, 2011 at 5:06 pm

    How does this condition relate to adrenal insufficiency?

    Posted December 13, 2011 at 10:53 am

    To Anne:
    I like to see the TSH at 2.0 or less and any thyroid antibody presence is worth exploring
    To Chris:
    All your points are extremely valid. First, men have a tendency to keep their symptoms to themselves and I agree that hypothyroidism in men is likely both underdiagnosed and undertreated. I have taken to ordering a thyroid profile (in addition to routine blood tests) whenever anyone comes in for a general check up and most physicians do (or should) check thyroid whenever a patient mentions the word ‘fatigue.’ Second, I did not mean to imply the antithyroid antibody issue was ‘women only’ and Hashimoto’s certainly does appear frequently in men. The published study was tracking only women. Third, a great many factors will set anyone’s immune system to start producing antibodies.The leaky gut issue (a/k/a intestinal hyperpermeability) for reasons that elude me remains ‘controversial’ among conventional physicians, but it is by measuring antibodies directed against foods that we test for food sensitivities. It is through a leaky gut that large food molecules ‘leaked’ and triggered the immune system to create antibodies. The immune complex of the food molecule + antibody can be pro-inflammatory. This is why avoidance of the culprit food AND healing of the leaky gut will often end the food sensitivity symptoms. Theoretically, the immune system could mis-read a leaked macromolecule (e.g. gluten) and start creating antithyroid antibodies instead. Hope this answers your very interesting questions.

    Dr. E
    Posted December 13, 2011 at 10:22 am

    As a man living with thyroid disease for most of my life, I have a few comments/questions:

    1) I know that most of the time it’s women who aren’t studied or treated well by the medical establishment. But in this case, I wonder if the constant emphasis on thyroid disease as a “women’s” problem means that men go undiagnosed and undertreated. Is the 20-to-1 ratio based on controlled studies of a large group of both males and females, or is it based in the sex of the people diagnosed with hypothyroidism? Could the number of men with the condition actually be higher but they aren’t recognized for some reason (cultural, or perhaps different symptoms appear first for men, etc.)

    2) I’ve certainly battled fatigue over the years. Is the thesis here that anti-thyroid antibodies cause fatigue–but only in women? I find the argument that this is related to women’s different immune systems unsatisfying. True, it makes no evolutionary sense for women’s immune systems to attack their developing fetuses, but nor does it make evolutionary sense to attack their thyroids such that they cannot become pregnant! I have long believed antibodies are important even though most doctors seem not to care at all. This is partially why I’ve always preferred a larger, almost suppressive dose of Armour–to keep the thyroid quiet and hopefully “unnoticed” by my immune system. I’ve always felt better on such a dose and I’ve always attributed this to reduced inflammation and antibodies.

    3) Speaking of inflammation, how do you regard newer theories suggesting that wheat gluten and “leaky gut” problems may actually be causing these problems? The theory goes something like this: gluten causes inflammation of the gut, whose barrier becomes permeable enough to allow proteins to escape into the blood where they provoke the immune system response that begins the constellation of auto-immune disorders often seen (often without any of most typical symptoms of celiac disease)? I read a report a year or two ago that people with any one auto-immune disorder were something like 70% more likely to have another (or more). What if they are all caused by the same process, beginning in the gut? I find it compelling, but also recognize that it’s the kind of theory that some will quickly dismiss as the ramblings of a conspiracy nut or something, particularly since a major part of the treatment would be diet, and the traditional medical establishment doesn’t believe that diet can meaningfully affect health or cure disease.

    Christopher Gagnon
    Posted December 13, 2011 at 8:48 am

    What are the various levels of TSH and antibodies we should be looking for?

    Posted December 13, 2011 at 8:25 am

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