While not often talked about publicly, all women understand that there are two major hormonal shifts in their lifespan as a female - menstruation and menopause. Both mark the beginning or end of fertility and physical changes within a woman's body, but many would argue that there is also an emotional and mental change during these two somewhat taboo events.
To make menopause even more difficult emotionally and mentally, sometimes physical symptoms may not all be due to menopause. Sometimes it's difficult for women to understand why they are feeling this way - is it the change in hormones due to menopause or something else?
What is menopause?
Menopause entails any of the changes or symptoms women of a certain age experience before or after they completely stop menstruating. It marks the end of a woman’s reproductive life and the menstruation cycle.
Technically, menopause starts when a woman’s menstruations have ceased for 12 months straight, as her ovaries no longer produce two main sex hormones — progesterone and estrogen. Some of the most common symptoms women experience during this intense period include irritability, sleep disturbances, night sweats, chills, hot flashes, and erratic periods. And to make it even harder to understand as a woman, perimenopause (the time between when menopause symptoms happen and true menopause) can last for months.
In some cases, however, these changes a woman can experience aren’t all related to menopause. The symptoms of hypothyroidism overlap with the symptoms of menopause, so the two can be easily confused. Women should be aware of a connection between hypothyroidism and menopause. Let’s look at the connection.
Get to know the thyroid gland
The thyroid gland is a small, butterfly-shaped endocrine gland located at the front of your neck, below the voice box. The little gland produces thyroid hormones that regulate metabolism and thus control how the body makes use of energy. In doing so, it influences the reproductive system, nearly every organ (including kidney, brain and heart). as well as biological functions such as appetite, hormonal balance, digestion, heart beat, and muscle strength.
The thyroid gland can go out of whack, pumping out an excess or lower amounts of thyroid hormones than the body needs. Hypothyroidism, a deficiency of thyroid hormones, is common and it affects nearly one out of every 20 Americans. Also known as underactive thyroid, it’s a condition in which the gland doesn’t make sufficient amounts of thyroid hormones to meet the body’s quota. Consequently, the pituitary gland floods the bloodstream with TSH (thyroid-stimulating hormone) to try to correct the shortfall.
How the thyroid works during the menopausal transition
During the perimenopause transition period, aging ovaries tend to produce unpredictable levels of the reproductive hormones progesterone and estrogen.
This irregular hormonal activity can be confusing for the body, resulting in erratic periods, mood swings, and hot flashes. Vaginal dryness, breast tenderness, night sweats, fatigue, difficulty sleeping, and forgetfulness are also quite common during perimenopause. Most women experience fluctuating hormonal symptoms in the eight years to a decade leading up to the actual menopause.
Hypothyroidism and menopause transition seem to go hand-in-hand, since both usually affect middle-aged women. This has led researchers to believe there might be a connection between perimenopause and thyroid function.
It all comes down to estrogen levels which decrease dramatically during the menopausal transition. As a result, menstruation cycles become longer, farther apart, and generally unpredictable. This stifles the hormonal balance throughout almost the entire body, including the pituitary’s TSH and thyroid hormones.
Irregular estrogen levels may also affect thyroid function. Specifically, estrogen affects the thyroid gland’s ability to produce enough triiodothyronine (T3) and thyroxine (T4) to meet the needs of the body. In response, the pituitary gland releases more TSH into the bloodstream in an attempt to stimulate the thyroid.
Remember: menopausal transition is an unpredictable process, so you can have low levels of estrogen some days and high amounts on others. When estrogen levels are especially high, it can have a positive effect on thyroid function.
The debate about the relationship between hypothyroidism and menopause has been ongoing for quite a while. That’s partly because thyroid function itself dwindles, albeit slowly, as we age. Also, less iodine is absorbed into the bloodstream as we age and, as a consequence, the thyroid gland produces insufficient levels of T4.
Low thyroid function has also been found to slow down the conversion of T4 into the more biologically active T3. This causes a domino effect that starts with the gallbladder and liver, and eventually circles back to the thyroid gland. It’s a vicious circle.
Even if a woman has never had thyroid issues, she may start to experience some symptoms associated with abnormal thyroid function during the menopausal transition.
This has led researchers to focus their attention on the potential connection between hypothyroidism and menopause transition.
A great example seeming to show the connection appeared in a 2011 review study published in the Journal of Thyroid Research in which a team of scientists evaluated the influence of estrogen levels on thyroid receptors. These are special protein molecules that bind to thyroid hormones and therefore usher them into cells where they regulate metabolism. Researchers concluded that estrogen levels may be linked to low thyroid function, and by extension, thyroid cancer and other thyroid disorders like hypothyroidism.
Relationship between estrogen and thyroid
As we’ve seen, multiple symptoms of hypothyroidism and menopause overlap. In fact, millions of women with symptoms typical of menopause, even some who are on estrogen therapy, may be unknowingly suffering from undiagnosed hypothyroidism.
The relationship between estrogen levels and thyroid function may be the missing link in our understanding of the connection between hypothyroidism and menopause. Normally, when a woman approaches menopause, her ovarian reserve starts to diminish. In turn, estrogen production in the ovaries declines.
It is well-documented that estrogen levels can have both indirect and direct effects on thyroid function. Estrogen is a highly bioactive hormone. Excess or insufficient levels in the body can have far-reaching effects. Your body requires just the right amount, and any deviation can affect the subtle relationship between estrogen and thyroid function.
Too much estrogen can interfere with your thyroid health. That’s because high blood levels of estrogen signal the liver to increase the production of thyroid-binding globulin (TBG). This is an inhibitor protein that binds to the thyroid hormone, reducing the amount of T3 and T4 available for use by cells. In response, the thyroid gland cranks up production to compensate for the deficit.
Estrogen can also affect thyroid function in other ways:
- Estrogen stimulates the growth of the thyroid gland. As a consequence, excess estrogen can lead to an enlarged thyroid (goiter); inadequate thyroid tissue results from too little estrogen.
- Estrogen regulates the protein that binds to the thyroid hormone (TBG) in the bloodstream. Too much can result in inadequate unbound thyroid hormones, which cause symptoms of underactive thyroid. These symptoms of hypothyroidism and menopause can magnify one another.
- Estrogen is also responsible for stimulating thyroglobulin, a thyroid hormone precursor. Excess estrogen causes goiter because of high levels of thyroglobulin. Likewise, too little estrogen results in low thyroglobulin, which reduces thyroid function.
TSH and menopause
High TSH normally indicates an underactive thyroid, since the pituitary gland floods the bloodstream with the hormone in a reactive attempt to stimulate the thyroid gland to produce more T4 and T3. Changes in the amount of estrogen produced by the ovaries during menopause can also affect the levels of thyroid hormones and TSH in the blood. Sometimes, it can be tricky to differentiate the symptoms of hypothyroidism and menopause since they are usually similar. For instance, moodiness, forgetfulness, depression, irregular menstrual cycles, and weight changes are associated with both hypothyroidism and menopause.
On the other hand, hyperthyroidism (overactive thyroid) and menopause can also share some symptoms, such as sleep disturbances, heart palpitations, heat intolerance, and hot flashes.
Hypothyroidism, hyperthyroidism, and other thyroid issues can elevate your risk of health complications linked to menopause, such as urinary tract infection, weight gain, insomnia, and heart disease.
Testing for thyroid and hormones
Given that there is a gray area between the symptoms of hypothyroidism and menopause, it’s only through testing that you can know for sure what your condition is. If you are found to have an underactive thyroid, your doctor can prescribe thyroid replacement therapy to normalize thyroid hormone levels. If it’s menopause, there are some medications you can take to alleviate certain annoying menopausal symptoms. Your OB/GYN may also recommend menopausal hormone therapy.
The good thing is that there are different types of tests you can take to see if there’s anything wrong with your thyroid if you’re going through menopause:
TSH tests and advanced thyroid testing
The TSH test is a great blood test that helps figure out if you have an early stage thyroid disorder. It measures the level of thyroid-stimulating hormone (TSH) in your blood. It may detect hypothyroidism or hyperthyroidism way before the levels of thyroid hormone in the body go out of whack.
A high TSH level means that your thyroid is underactive and you possibly have hypothyroidism. On the other hand, a low TSH level typically indicates an overactive thyroid, and that the gland is producing too much thyroid hormone.
If there’s an anomaly — for instance, a tumor or inflammation — that is hindering the pituitary gland from stimulating the thyroid gland enough, the test will also return a low TSH result. This is referred to as secondary hypothyroidism.
If your TSH test comes back as abnormal, there are other thyroid tests that your OBGYN, endocrinologist, or physician can order to get to the root issue of your thyroid imbalance including:
- T4 Tests (Total T4, FT4, and FTI) - The thyroid gland produces 94% T4 and only 6% T3. The blood has special proteins that bind to T4 and T3 during circulation. A Total T4 returns the aggregate level of both free and bound T4 hormone; it’s not the most accurate blood test when checking if the thyroid is functioning properly. Alternatively, your doctor may order a free T4 index (FTI) or free T4 (FT4) test. The latter test is most informative.
- T3 Tests - A T3 blood test is more reliable when diagnosing an overactive thyroid (hyperthyroidism). It may not do much for someone with hypothyroidism and menopause symptoms.
- Free T3 Test - You can also measure free T3. This test is rarely ordered because it’s frequently uninformative.
- Thyroid Antibody Tests - In a healthy body, the immune system releases antibodies into the bloodstream to help fight off viruses, bacteria, and other foreign invaders. In most people with an underactive or overactive thyroid, the immune system can “see” the thyroid as a foreign invader and manufacture antibodies against its cell proteins. Thyroid antibody tests measure the presence and levels of two major antibodies made against thyroid cell proteins: thyroglobulin antibody, and thyroid peroxidase antibody. If you have overlapping symptoms of hypothyroidism and menopause, these antibody tests may help make a conclusive diagnosis in combination with others like TSH, T3, and T4.
- Radioactive Iodine Uptake (RAIU) Test - A very low RAIU is sometimes used as a possible indication of hypothyroidism, while a high RAIU may help diagnose an overactive thyroid. But this is an antiquated test.
The most definitive way to know if you’ve got a thyroid problem is through the above-mentioned blood tests.
When should you consider testing?
If you’ve been gaining weight, or your LDL cholesterol has been going up unexplainably, you should consider getting tested. If you have other definite symptoms of hypothyroidism – like cold sensitivity, slowed heart rate, a puffy face, or goiter (swelling around the neck), you should speak with your doctor about being tested.
If you’re a senior older than sixty, you may benefit from getting tested even if you are generally healthy. A blood TSH test is the single most sensitive and reliable test when checking for an underactive or overreactive thyroid.
When to consult a doctor
Millions of women suffer from both hypothyroidism and menopause symptoms. The more you know about your situation, the better. Consult your physician if you’re experiencing any of the symptoms of hypothyroidism and/or menopause.
Make sure to tell your doctor any symptoms you have been experiencing, particularly moodiness, weight changes, hot flashes, irregular menstrual cycle, and fatigue. Inform your doctor of any family history of thyroid-related disorders.