Is there a link between menopause and an underactive thyroid?
Menopause is the time in a woman's life when her periods stop, and she is no longer able to have children. When people talk about menopause symptoms, they often refer to symptoms associated with perimenopause, the time of transition to menopause.
When the thyroid gland produces too much or too little thyroid hormone, it can cause many different symptoms, some of which are very similar to the symptoms experienced by a woman in or entering menopause.
In this article, we look at the link between these two conditions, including how one might affect the other, and what the outlook is.
Estrogen and the thyroid gland
Some perimenopause symptoms are similar to those for an underactive thyroid.
Thyroid problems are significantly more common in women, especially when they are of childbearing age.
This may be because of the relationship between thyroid function and estrogen, the primary sex hormone of women.
A 2011 study published in the Journal of Thyroid Research reported that there is "evidence that estrogen may have direct actions in human thyroid cells."
In the time leading up to menopause, estrogen levels fall significantly, which would undoubtedly affect thyroid levels. More research is needed to determine the relationship, however.
Symptoms of an underactive thyroid and menopause
It can sometimes be difficult to tell apart the symptoms of an underactive thyroid (hypothyroidism) and menopause because they are very similar.
The table below compares the symptoms of both menopause and an underactive thyroid.
The transition to menopause often begins when a woman reaches 45 to 55 years old. Thyroid disease can begin at any age.
Women of menopausal age are also more to develop an overactive thyroid (hyperthyroidism); however, this is less common than an underactive thyroid.
As with an underactive hyperthyroid, it can produce similar symptoms to menopause, including:
Other common symptoms of hyperthyroidism include weight loss, an enlarged thyroid, and bulging eyes. Common treatments include antithyroid drugs, radioactive thyroid therapy, and surgery.
Risks and complications
Thyroid problems can increase the risk of complications that are associated with menopause. For instance, during menopause, women are more likely to develop osteoporosis — a condition where bone density is reduced. An overactive thyroid can also increase the risk of the condition.
Similarly, during menopause, the risk of cardiovascular disease increases; thyroid conditions also increase the risk. In this way, thyroid problems may interact to increase the likelihood of complications developing during menopause.
When to see a doctor
A blood test can diagnose both an underactive thyroid and menopause.
A woman experiencing any of these symptoms should check in with her doctor and not just assume that they are due to menopause or perimenopause.
The doctor can perform tests to definitively diagnose whether a woman is experiencing menopausal symptoms, or whether she has an underactive thyroid.
The doctor will ask questions about the symptoms, such as when they began, how severe they are, and how long they have lasted. The doctor will likely perform a physical exam and may suggest diagnostic testing.
Both menopause and an underactive thyroid can be diagnosed with a simple blood test that checks levels of the following things:
Follicle stimulating hormone (FSH)
FSH is the hormone responsible for inducing maturation and ovulation of an egg in the ovary.
As a woman ages, her body needs more FSH to do this.
Persistently raised levels of FSH — usually over 30 milli-international units per milliliter (mIU/mL) — can indicate menopause.
Luteinizing hormone (LH)
LH is also persistently raised after menopause.
A woman will have more LH in the middle part of her menstrual cycle — the release of LH is what triggers ovulation — so a single elevated value will not definitively diagnose menopause.
Thyroid stimulating hormone (TSH)
Checking the levels of TSH is often the first test that doctors will do to see how the thyroid gland is working.
When the thyroid is not working correctly, the body produces TSH to stimulate the thyroid into producing thyroid hormones. A high TSH level can indicate an underactive thyroid.
T3 and T4
These are the two main hormones that the thyroid gland produces.
Levels do not change significantly with an underactive thyroid, but doctors carry out the test to rule out other thyroid conditions.
Thyroid antibody testing
The thyroid gland contains cell proteins, and sometimes the body produces antibodies against these proteins. If this happens, it can cause both underactive and overactive thyroid disease.
If these antibodies are present in someone with an underactive thyroid, then a doctor may diagnose Hashimoto's thyroiditis.
Relationship between menopause and thyroid conditions
Some women take hormone replacement therapy (HRT) to help reduce the symptoms associated with perimenopause.
Most women do not have any issue with their thyroid after starting HRT. However, some women who are already taking medication for an underactive thyroid may find that they need to adjust the dose of their thyroid medication.
It is important to have thyroid hormone levels rechecked from time to time, especially if a woman is experiencing any of the symptoms associated with an underactive thyroid or menopause.
There is also some concern about the use of soy supplements by women transitioning to menopause because of their adverse impact on thyroid function. The British Thyroid Foundation suggest that it is unlikely that soy affects women with normal thyroid function.
However, women who have borderline thyroid function and do not take in enough iodine — the thyroid gland converts iodine into T3 and T4 — may have an increased risk for an underactive thyroid if they eat a lot of soy.
Women who choose to take a soy supplement and have low thyroid function should be sure that they are eating enough iodine, which can be found in ordinary table salt.
The dose of thyroid medication may also need to be adjusted, as there is some evidence that soy can block thyroid medication from being absorbed.
Some health concerns associated with menopause and underactive thyroid include:
The loss of estrogen can increase the risk of osteoporosis and bone fractures.
Osteoporosis is a condition where a person's bones are weaker and more prone to damage.
Both estrogen and the thyroid hormones can help bones to stay strong and healthy. Both menopause and an underactive thyroid result in a loss of estrogen, which increases the risk for fracture.
Seeing the doctor for regular bone density screening tests and hormone testing can help with early detection of osteoporosis.
Also, eating a diet rich in calcium and taking calcium supplements if needed can help to promote bone health.
Women experiencing menopause and have an underactive thyroid may find that they gain weight. Weight gain is also very common with increasing age.
It is important to increase activity and decrease food intake to help reduce the risk of putting on extra weight.
Untreated underactive thyroid
Anyone experiencing these symptoms should see a doctor for an evaluation.
With treatment and regulation of thyroid hormones, the outlook for someone with an underactive thyroid is excellent. This condition is widespread and is readily controlled with medication.
Menopausal symptoms may cause some discomfort for several years, but it is a natural transition, and most women have no issues once it is complete.
The relationship between an underactive thyroid and menopause is quite complicated, and there are a lot of factors involved. The symptoms of each of these conditions can be quite similar and sometimes the two interact in a way that can increase their severity.
It is important to find a doctor who listens and can provide the guidance necessary to get an accurate diagnosis and effective treatment plan.