It weighs around 20 grams and sits just below the larynx – yet it controls the rate at which every cell in the body ages. The thyroid produces hormones that regulate metabolism, temperature, heart function, and mood. After the age of 40, its function often shifts, and Hashimoto’s has become one of the most common autoimmune conditions across Europe. Discover how to recognise the warning signs and what genuinely supports the gland for years to come.
Key facts about the thyroid:
- Thyroid hormones regulate the metabolism of every cell in the body
- Hashimoto’s affects 5-10% of the population, more often women over 30
- Early symptoms are subtle and often mistaken for stress or ageing
- TSH, FT3, FT4 and antibodies form the foundation of thyroid diagnosis
- Selenium, iodine and vitamin D support gland function through daily diet
What is the thyroid?
The thyroid is a small butterfly-shaped gland just below the thyroid cartilage. It weighs 15-25 grams but produces hormones that reach every tissue in the body.
What does the thyroid do?
The thyroid governs the pace of metabolic processes. It regulates energy, temperature, heart function, and tissue repair. It influences heart rate, blood pressure, gut motility, and skin quality.
What hormones does the thyroid produce?
The thyroid produces two main hormones – thyroxine (T4) and triiodothyronine (T3) – using iodine taken from food. T4 makes up around 80% of secreted hormones, but T3 is the biologically active form, mostly converted from T4 in the liver, kidneys, and muscles.
What are the symptoms of thyroid problems?
Thyroid symptoms are often non-specific and easily mistaken for fatigue or ageing – which is why diagnosis is typically delayed by several years. The key is observing combinations of signals. When several appear at once and persist for weeks, it’s worth checking TSH levels.
Signs worth checking with an endocrinologist:
- Persistent fatigue despite getting enough sleep
- Weight changes without changes to diet or activity
- Hair loss and brittle, splitting nails
- Dry skin, feeling cold or, conversely, excessive sweating
- Mood changes, problems with concentration and memory
How does hypothyroidism differ from hyperthyroidism?
Hypothyroidism
In hypothyroidism, fatigue, weight gain, cold intolerance, dry skin, and low mood appear. TSH is elevated and FT4 is reduced. The most common cause across Europe is Hashimoto’s.
Hyperthyroidism
In hyperthyroidism, metabolism speeds up – resulting in weight loss, palpitations, hand tremors, anxiety, and insomnia. TSH is suppressed while FT3 and FT4 are elevated. The most common causes are Graves’ disease and autonomous nodules (parts of the gland producing hormones outside the brain’s control).
What are the causes and risk factors of thyroid disease?
Thyroid diseases combine genetic predisposition, environmental factors, and hormonal influences. Women are affected 5-8 times more often than men, with risk rising after childbirth, during perimenopause, and following prolonged stress. Iodine deficiency, smoking, and certain infections can trigger autoimmune processes.
What is Hashimoto’s disease?
Hashimoto’s is a chronic thyroiditis in which the immune system produces antibodies attacking the gland’s own cells. Hallmarks include anti-TPO (against thyroid peroxidase) and anti-TG (against thyroglobulin) antibodies, plus a typical ultrasound picture. The frequency of Hashimoto’s is rising in developed countries, which researchers link to exposure to endocrine disruptors (substances that interfere with hormone balance).
How is thyroid disease diagnosed?
Basic diagnosis relies on blood tests. Measuring TSH along with free hormones FT3 and FT4, supplemented by anti-TPO and anti-TG antibodies when Hashimoto’s is suspected. Blood is taken in the morning on an empty stomach, when TSH levels are highest.
What are the reference ranges for TSH, FT3, FT4 and antibodies?
The reference range for TSH in adults is 0.4-4.0 mU/L, although some researchers consider values above 2.5 mU/L a signal warranting further investigation. FT4 and FT3 ranges depend on the laboratory method and are listed on the result form – what matters is comparison with each laboratory’s specific range.
When should you have a thyroid ultrasound and other imaging tests?
A thyroid ultrasound is performed when hormone results are abnormal, the neck appears enlarged, or as part of Hashimoto’s monitoring. A practical tip: if you have monitoring ultrasounds, request the same clinic and the same radiologist – comparing changes over time is more reliable than a single isolated result.
How is thyroid disease treated?
Treatment depends on the diagnosis – hypothyroidism requires lifelong thyroid hormone therapy, while hyperthyroidism may be treated pharmacologically, with radioactive iodine, or surgically. Treatment is supervised by an endocrinologist or general practitioner, who selects the dose and monitors TSH every 6-12 weeks at the start of therapy.
Can Hashimoto’s be cured?
Hashimoto’s cannot be permanently cured, but its course can be effectively managed. The aim of treatment is to balance hormone levels and slow disease progression. Research on microbiome health suggests that gut condition significantly influences autoimmune activity.
What does thyroid disease prevention look like?
Prevention is built on supplying nutrients essential for hormone production and avoiding factors that strain the gland. Iodine, selenium, zinc, iron, and vitamin D form the foundation. Equally important is limiting exposure to endocrine disruptors, regular movement, and managing stress.
Practical pillars of thyroid prevention:
- Iodised salt in everyday cooking and 1-2 portions of sea fish weekly
- Brazil nuts as a natural source of selenium (1-2 daily)
- Vitamin D supplementation in autumn and winter, guided by 25(OH)D testing
- 7-8 hours of sleep and regular meal times stabilising hormonal rhythms
- Limiting alcohol and tobacco, plus exposure to BPA and phthalates
How does the thyroid affect weight and metabolism?
Thyroid hormones govern the rate of basal metabolism. Hypothyroidism slows metabolism by 15-40%, which explains weight gain despite an unchanged diet. Controlled hypothyroidism rarely causes a gain greater than 3-5 kilograms – most weight difficulties stem from other mechanisms: insulin resistance, stress, or cellular ageing.
What diet supports thyroid function?
The thyroid needs micronutrients – iodine as a building block, selenium for converting T4 to T3, plus zinc, iron, and vitamin D. A good model is the Mediterranean diet, combining sea fish, olive oil, vegetables, nuts, and fermented dairy products.
The second pillar is gut health – the microbiota influences thyroid hormone activation. Fermented foods such as kefir, sauerkraut, and natural yoghurt deliver probiotics that support the gut barrier.
What exercise and lifestyle support the thyroid?
Regular movement improves tissue sensitivity to thyroid hormones and lowers cortisol. The best results come from combining cardio (3-4 times a week, 30-45 minutes) with strength training (2-3 times a week).
Chronic stress triggers autoimmune processes. 7-8 hours of sleep and consistent meal times stabilise the hypothalamic-pituitary-thyroid axis.
The thyroid – when to act and who to turn to
The first step is to have TSH measured by a general practitioner – enough for an initial assessment of thyroid function. If results are abnormal, the doctor refers you for FT3, FT4, and antibodies and, if needed, to an endocrinologist.
The above text is for educational purposes and does not replace medical consultation. If you suspect thyroid disease, consult an endocrinologist or general practitioner.
FAQ: Frequently asked questions about the thyroid
Which doctor should you see for thyroid issues?
The first appointment is best made with a general practitioner, who will order basic tests (TSH, possibly FT4) and refer you, if needed, to an endocrinologist.
What is the normal range for TSH?
The standard reference range for TSH in adults is 0.4-4.0 mU/L, although some endocrinologists consider values above 2.5 mU/L a sign warranting observation, particularly in women planning pregnancy.
Can Hashimoto’s be cured?
Hashimoto’s is a chronic disease that cannot be permanently cured, but its course can be managed through hormone therapy, an anti-inflammatory diet, selenium supplementation, and stress reduction.
Which nutrients are important for thyroid function?
The most important nutrients are iodine (sea fish), selenium (Brazil nuts), zinc (meat, pumpkin seeds), iron (lean meat) and vitamin D (autumn-winter supplementation).
References:
- Caturegli, P., De Remigis, A., & Rose, N. R. (2014). Hashimoto thyroiditis: Clinical and diagnostic criteria. Autoimmunity Reviews. https://doi.org/10.1016/j.autrev.2014.01.007
- Ventura, M., Melo, M., & Carrilho, F. (2017). Selenium and thyroid disease: From pathophysiology to treatment. International Journal of Endocrinology. https://doi.org/10.1155/2017/1297658
- Wiersinga, W. M. (2014). Paradigm shifts in thyroid hormone replacement therapies for hypothyroidism. Nature Reviews Endocrinology. https://doi.org/10.1038/nrendo.2013.258
