Menopause & thyroid: when hormones fall out of balance

The thyroid gland: small but vital

The thyroid gland is located at the front of the neck, below the larynx, and produces essential hormones, primarily T3 (triiodothyronine) and T4 (thyroxine). These hormones regulate the energy consumption of cells—that is, the body’s overall metabolism. Even slight deviations in hormone production can have noticeable effects on both the body and the mind.

While the thyroid gland often performs its work unnoticed in younger years, functional disorders become more common with age. Women are particularly affected—and the risk increases significantly with the onset of menopause.

Why menopause puts a strain on the thyroid—and vice versa

As estrogen levels decline, the body’s entire hormonal balance shifts—and this also affects the thyroid. At the same time, suboptimal thyroid function can exacerbate or mimic typical menopausal symptoms. These include:

• •Sleep disturbances
• •Difficulty concentrating (“brain fog”)
• •Mood swings, including depression
• •Weight gain or unexplained weight loss
• •Heart palpitations or inner restlessness
• •Increased sensitivity to cold or heat

The challenge: Many of these symptoms are nonspecific—they can be caused by hormonal fluctuations during menopause as well as by a thyroid disorder. This makes it all the more important to consult a doctor for a thorough evaluation.

Precisely because many of these symptoms are so similar, it is often difficult to distinguish between them in everyday life. Sleep disturbances, depressive moods, heart palpitations, or weight fluctuations—all of these can be triggered by both the hormonal changes of menopause and by an underactive or overactive thyroid. This not only complicates diagnosis but also carries the risk that symptoms will remain untreated for too long.

The following table shows how closely the typical symptoms of menopause are intertwined with those of thyroid disease—and where differences may become apparent. Such an overview can be an important impetus for seeking a targeted evaluation of possible causes.

Hypothyroidism, hyperthyroidism—or both?

There are two main types of thyroid dysfunction:

• •Hypothyroidism: The body produces too few thyroid hormones. Typical symptoms include lethargy, feeling cold, constipation, dry skin, and weight gain. A common cause is an autoimmune disorder (Hashimoto’s thyroiditis).
• •Hyperthyroidism (overactive thyroid): In this case, the thyroid gland produces too many hormones. The result: nervousness, sleep problems, heart palpitations, weight loss despite a good appetite, and hot flashes—symptoms that are often mistakenly attributed solely to menopause.

In both cases, the symptoms can begin subtly and develop gradually—often over the course of years. Especially during perimenopause, thyroid disorders are therefore frequently overlooked or diagnosed too late.

A focus on hyperthyroidism: when the thyroid glands are overactive

Hyperthyroidism can also occur during menopause — and its symptoms resemble a hormonal storm. Hot flashes, heart palpitations, restlessness, sleep problems, and unintentional weight loss can indicate both a decline in estrogen and hyperthyroidism. In some women with Hashimoto’s disease, a condition known as Hashitoxicosis occurs early in the course of the disease—a temporary phase with symptoms of overactivity before hypothyroidism sets in later. Anyone going through menopause who suddenly notices hot flashes accompanied by heart palpitations or a low TSH level should have this checked by their doctor—a simple blood test can provide clarity.

Testing your thyroid – when is the right time?

If you're in menopause and experiencing symptoms that are hard to explain – such as persistent fatigue, unexplained weight gain, or heart palpitations – a blood test can provide clarity. The most important lab values include:

• •TSH (thyroid-stimulating hormone): Indicates how strongly the pituitary gland is stimulating the thyroid to produce hormones.
• •Free T4 and Free T3: Show how much active hormone is actually available in the body.
• •Antibodies (TPO-Ab, TG-Ab): Help identify autoimmune diseases like Hashimoto’s thyroiditis.

Important: a single test result is often not enough. Especially during perimenopause, hormonal levels can shift significantly within just a few months – regular testing is therefore advised.

TSH reference ranges by life stage

The following table provides general reference ranges. Your individual target range may differ—for example, during pregnancy, while undergoing treatment for Hashimoto’s disease, or when taking L-thyroxine. Always discuss your results with your doctor or endocrinologist.

The thyroid gland and hormone replacement therapy (HRT)

Many women with thyroid problems wonder whether they can start hormone replacement therapy despite their diagnosis. The good news is that in most cases, this is possible without any problems. However, there are a few things to keep in mind:

• •Estrogen administered through the skin (e.g., as a gel or patch) does not interfere with thyroid medication. This makes this form particularly suitable for many women with hypothyroidism.
• •Oral estrogen (tablets) can increase the need for thyroid hormones, as it alters the binding of thyroxine in the blood. Anyone taking tablets should have their thyroid levels monitored closely after starting HRT.
• •Progesterone and testosterone have no significant effect on thyroid function.

One thing is particularly important: the thyroid must be well-regulated—only then can HRT be fully effective.

Thyroid, bone health, and heart

An undiagnosed or untreated deficiency in thyroid hormones can not only affect overall well-being but also have tangible physical consequences—especially when combined with the estrogen deficiency associated with menopause:

• •Osteoporosis: Both hyperthyroidism and “overtreated” hypothyroidism increase the risk of bone loss and fractures.
• •Cardiovascular diseases: A TSH level that is too low (e.g., due to an overdose of L-thyroxine) can significantly increase the risk of cardiac arrhythmias and heart attacks.

Therefore, it is important to take not only the symptoms but also the long-term consequences seriously—and to have your thyroid levels checked regularly.

What you can do – practical recommendations

• •Take symptoms seriously: Fatigue, weight gain, or heart palpitations should not be dismissed as “just menopause.” Talk to your doctor about the possibility of thyroid dysfunction.
• •Check lab values regularly: Especially if you already have a thyroid condition or are undergoing HRT, your TSH level should be tested at least once a year – more frequently if abnormalities are detected.
• •Choose supplements carefully: Iodine, calcium, and soy can affect how thyroid medications work. Only take them after consulting with your doctor.

Be aware of the interactions: HRT, thyroid hormones, and supplements should be spaced out throughout the day so they don’t interfere with each other. Medical advice can help you organize this properly.

Good to know:

• •Regular soy consumption requires adequate iodine intake – especially if thyroid function is borderline.
• •Calcium supplements can interfere with the absorption of thyroid hormones. Leave at least four hours between taking them.
• •Excessive iodine intake – for example, through kelp products – can worsen existing thyroid conditions.

Thyroid & menopause – keep both in focus

 The thyroid is often an underestimated factor during menopause. Its function can intensify, mask, or even cause symptoms – and it also affects the success of hormone replacement therapy. That’s why it’s essential to keep an eye on both: your sex hormones and your thyroid hormones.

If you’re unsure, speak to your doctor – and insist on a thorough examination. Because only when all the hormonal building blocks fit together can you feel stable, energized, and at home in your body during this important phase of life.

References

• •Mintziori G, Veneti S, Poppe K, Goulis DG, Armeni E, Erel CT, Fistonić I, Hillard T, Hirschberg AL, Meczekalski B, Mendoza N, Mueck AO, Simoncini T, Stute P, van Dijken D, Rees M, Duntas L, Lambrinoudaki I. EMAS position statement: Thyroid disease and menopause. Maturitas. 2024 Jul;185:107991. Epub 2024 Apr 24. PMID: 38658290. https://pubmed.ncbi.nlm.nih.gov/38658290/
• •Frank-Raue K, Raue F: Thyroid dysfunction in peri- and postmenopausal women—cumulative risks. Dtsch Arztebl Int 2023; 120: 311–6. https://pubmed.ncbi.nlm.nih.gov/37013812/
• •British Thyroid Foundation. Thyroid and menopause [Internet]. British Thyroid Foundation; 2024 [cited 2025 May 18]. Available from: https://www.btf-thyroid.org/thyroid-and-menopause-article

This article is not a substitute for medical advice. If you have any symptoms, please consult your family doctor or endocrinologist.