The Thyroid: Small but Essential

The thyroid is located at the front of the neck, just below the larynx, and produces vital hormones – mainly T3 (triiodothyronine) and T4 (thyroxine). These hormones regulate the body's energy use – in other words, the entire metabolism. Even slight deviations in hormone production can have noticeable effects on both body and mind.

While the thyroid often functions quietly in the background during younger years, dysfunctions become more common with age. Women are particularly affected – and the risk increases significantly during the menopausal transition.

Why Menopause Strains the Thyroid – and Vice Versa

As estrogen levels drop, the body’s overall hormonal balance shifts – and the thyroid is affected as well. At the same time, a poorly regulated thyroid can intensify 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 heat or cold

The challenge: many of these symptoms are non-specific – they can be caused by hormonal changes of menopause, thyroid dysfunction, or both. That’s why a thorough medical evaluation is so important.

This symptom overlap is one of the key reasons why thyroid disorders in midlife women are often misdiagnosed or attributed solely to menopause. For instance, signs like sleep disturbances, difficulty concentrating, mood swings, weight fluctuations, heart palpitations, or changes in temperature sensitivity – all mentioned above – are not exclusive to menopause. They are also frequently seen in both hypothyroidism and hyperthyroidism.

The following table offers a structured comparison of how these and other symptoms occur across menopause and the two main types of thyroid dysfunction. Recognizing such overlaps can improve diagnostic accuracy and ensure the right treatment approach.

Underactive, Overactive – or Both?

There are two main types of thyroid dysfunction:

• •Hypothyroidism (underactive thyroid): The body doesn’t produce enough thyroid hormones. Typical signs include fatigue, feeling cold, constipation, dry skin, and weight gain. The most common cause is an autoimmune disease (Hashimoto’s thyroiditis).
• •Hyperthyroidism (overactive thyroid): Here, the thyroid produces too many hormones. The result: nervousness, sleep problems, heart palpitations, weight loss despite good appetite, and hot flushes – symptoms that are often mistakenly attributed to menopause alone.

In both cases: the symptoms can start subtly and develop gradually – often over several years. Thyroid disorders are particularly likely to be overlooked or diagnosed late during perimenopause.

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.

Thyroid, Bone Health, and Heart

An undetected or untreated deficiency in thyroid hormones can affect not only your general well-being but also have tangible physical consequences – especially when combined with the estrogen loss of menopause:

• •Osteoporosis: Both overactive and overtreated underactive thyroids increase the risk of bone loss and fractures.
• •Cardiovascular disease: A TSH level that is too low (e.g., from overmedication with levothyroxine) can significantly raise the risk of heart rhythm disturbances and heart attacks.

That’s why it’s crucial to take not just the symptoms, but also the long-term effects seriously – and to monitor thyroid levels 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.

Mind 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. doi: 10.1016/j.maturitas.2024.107991. Epub 2024 Apr 24. PMID: 38658290.

Frank-Raue K, Raue F: Thyroid dysfunction in peri- and postmenopausal women—cumulative risks. Dtsch Arztebl Int 2023; 120: 311–6. DOI: 10.3238/arztebl.m2023.0069

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