What is the thyroid gland?

The thyroid is a small, butterfly-shaped organ in the neck, located just below the larynx. It moves when swallowing and produces hormones that regulate metabolism, energy, and body heat.

The thyroid is a small, butterfly-shaped organ that lies in the neck just below the larynx, under the skin and a thin layer of neck muscles. This makes it easy to feel and it moves when swallowing. It consists of two lobes, located on either side of the windpipe, connected by a band-shaped bridge called the isthmus. Its main function as glandular tissue is to produce and release thyroid hormones. It does this in close coordination with the pituitary gland, which monitors the amount of thyroid hormone in the blood. The pituitary regulates the body’s need for thyroid hormones, and the thyroid responds by releasing more or fewer hormones accordingly.

The thyroid produces thyroid hormones, which are essential for processes such as energy balance and heat regulation.

Its hormones affect nearly all organs: the heart and circulation, digestion, muscle and nerve function, skin, hair, mood, and temperature regulation.

On the back of the thyroid sit four very small glands. They produce parathyroid hormone (PTH), which regulates blood calcium levels – important for bones, muscles, and nerves.

The parathyroid glands are small, lens-shaped organs found on the back of the thyroid. Their function is to produce parathyroid hormone (PTH), which plays a major role in regulating calcium and phosphate levels in the blood. Calcium is an electrolyte – a salt in the blood – that is essential for basic cellular functions and muscle cell activity. The body’s largest calcium store is in the bones, especially the long tubular bones. PTH causes calcium to be released from bone into the blood, increases absorption in the intestine (together with vitamin D3), and reduces excretion through the kidneys. At the same time, PTH increases phosphate excretion in the urine, preventing high phosphate levels in the blood that could otherwise cause calcium precipitation.

Mainly T4 (thyroxine) and T3 (triiodothyronine). T4 is largely converted into T3, which is more biologically active. A portion of the hormones circulate freely (fT4, fT3) – these are measurable in the blood and biologically active.

We distinguish mainly between two hormones: T4 (tetraiodothyroxine) and T3 (triiodothyronine), with T4 being a conversion product of T3. T3 is produced in the thyroid and converted into T4. Both are stored in special storage compartments called follicles. When the thyroid receives signals from the pituitary that more thyroid hormones are needed, T4 is increasingly converted to T3 and both hormones are released. In the blood, they can bind to a special transport protein, thyroglobulin (Tg). The unbound fractions are called free T3 (fT3) and free T4 (fT4).

Symptoms are often nonspecific, vary from person to person, and depend on the degree of dysfunction. Typical signs are:

Overactive thyroid (hyperthyroidism): rapid heartbeat, inner restlessness, tremors, sweating, sleep problems, unintended weight loss, frequent bowel movements.
Underactive thyroid (hypothyroidism): fatigue, sensitivity to cold, low drive/depressive mood, dry skin, brittle nails, constipation, weight gain.

A nodule is a local tissue overgrowth. Most nodules are benign; only about 5% are malignant. Clarification is done with ultrasound, sometimes scintigraphy, and fine needle aspiration.

Thyroid nodules result from increased cell division of thyroid tissue. This does not necessarily mean malignancy – in fact, only 5% are cancerous. The vast majority are benign.

These are fluid-filled cavities within organs, including the thyroid. Cysts are usually benign but can grow large and press on the windpipe, nearby nerves, or muscles, causing symptoms.

“Hot” means the nodule takes up a lot of tracer in scintigraphy and produces hormones independently of the body’s needs (autonomous). This can trigger hyperthyroidism.

A diagnosis is made by thyroid scintigraphy. “Hot” nodules produce thyroid hormones independently of the regulatory signals from the pituitary and thyroid. They are often called autonomous adenomas and can lead to hyperthyroidism, with symptoms such as palpitations, heat intolerance, and sweating.

“Cold” means the nodule takes up less tracer than the surrounding tissue. This may suggest malignancy but must always be evaluated with ultrasound.

Cold nodules show reduced or no tracer uptake in scintigraphy compared to healthy thyroid tissue. This can suggest malignant tissue, though only 2–5% are truly cancerous. Ultrasound is essential to evaluate the nodule’s location and structure and to determine which nodules require scintigraphy.

Dysfunction (over- or underactivity) can disrupt the menstrual cycle and reduce fertility. During pregnancy, well-regulated thyroid levels are important for the child’s development.

The thyroid plays a key role in egg cell maturation. Both hyper- and hypothyroidism can disturb the cycle and impair fertility. Hypothyroidism in pregnancy increases the risk of developmental problems in the child, while hyperthyroidism increases the risk of miscarriage, especially in early pregnancy.

In the first trimester, pregnancy hormone β-HCG rises and stimulates the maternal thyroid (peaking around week 10). In women with pre-existing thyroid disease, the risk of miscarriage rises without treatment. Thyroid function should therefore be checked early.

At the beginning of pregnancy, thyroid function changes in several ways. The pregnancy hormone beta-HCG rises (peak around week 10) and stimulates the thyroid. If stimulation is inadequate (e.g., due to pre-existing thyroid damage), the risk of miscarriage or malformations increases. In such cases, thyroid medication must be adjusted promptly. Ideally, thyroid values should be checked before or immediately after conception.

The immune system produces antibodies against thyroid tissue. Over years, this leads to recurrent inflammation and often hypothyroidism. Early on, temporary phases of hyperthyroidism may also occur.

This is an autoimmune disease in which the immune system forms antibodies against thyroid structures. These cause repeated inflammation over years or decades, leading eventually to hypothyroidism as functional cells are destroyed. Early on, temporary hyperthyroidism may occur. The term Hashimoto thyroiditis is often used synonymously, though technically it is not identical.

  • Manifest hyperthyroidism: low TSH, high fT3/fT4, usually clear symptoms.
  • Subclinical hyperthyroidism: low TSH, normal fT3/fT4.
  • Manifest hypothyroidism: high TSH, low fT3/fT4, usually clear symptoms.
  • Subclinical hypothyroidism: high TSH, normal fT3/fT4.

Antithyroid drugs slow down thyroid hormone production (e.g., thiamazole, carbimazole, propylthiouracil). They are used to treat hyperthyroidism.

These include thionamides (such as thiamazole, carbimazole, and propylthiouracil), which block hormone production, and iodine uptake inhibitors such as perchlorate.

An autoimmune-related inflammation in the eye socket (often in Graves’ disease). Typical signs: bulging eyes, pressure and foreign-body sensation, light sensitivity, vision problems. Early diagnosis is crucial.

The term describes the forward displacement of the eyeball due to metabolic dysregulation. In Graves’ disease, inflammation caused by autoantibodies leads to swelling of fatty tissue behind the eye, pushing the eyeball outward.

Ultrasound is a basic diagnostic tool for thyroid disease: size, structure, and nodules can be visualized, measured, and documented – quickly, painlessly, and without radiation.

When the function of a nodule or the entire thyroid must be evaluated. A weakly radioactive tracer is given; uptake strength shows whether tissue is “hot” (active) or “cold” (less active).

To obtain cells from a nodule or cyst. Guided by ultrasound, a thin needle is inserted, and the material is analyzed by pathology. The procedure is short, well tolerated, and usually does not require anesthesia.

Indications include:

  • malignant findings
  • markedly enlarged nodular thyroid with breathing/swallowing problems
  • therapy-resistant hyperthyroidism
  • rare purulent inflammations
  • very large, symptomatic nodules/cysts

Often, the affected lobe or the entire thyroid is removed to avoid repeat surgery.

A minimally invasive procedure: a fine probe delivers high-frequency energy to a nodule, shrinking or destroying it. RFA is suitable for selected, benign (proven) single nodules or very small thyroid cancers (microcarcinomas). Healthy tissue is spared.

A malignant thyroid disease. Surgery is usually the main treatment; additional therapies may follow. Prognosis is very good – 5-year survival is around 95–98%.

A capsule containing radioactive iodine-131 is swallowed. It accumulates in thyroid cells and destroys them from within. Indications: after thyroid cancer surgery or in hyperthyroidism (autonomous adenoma, Graves’ disease), depending on the case.

Iodine is a trace element needed to produce thyroid hormones. It is absorbed from food. In Austria, table salt has long been iodized to improve supply.

Ensure adequate iodine intake (e.g., iodized salt, dairy, eggs, sea fish). During pregnancy and breastfeeding, needs increase. Austria is a traditional iodine-deficient region, so supplementation is especially important.

* Click to learn more

What is osteoporosis?

Translated as “bone loss,” osteoporosis is often an age-related disease. Reduced bone mineralization lowers bone density, making bones fragile.

Primary osteoporosis: age-related (esp. after age 60–70), often due to calcium/vitamin D deficiency.
Secondary osteoporosis: due to other diseases (e.g., hormonal disorders, inflammatory diseases, kidney/gut diseases) or medications (e.g., long-term corticosteroids). Lack of exercise, malnutrition, and high alcohol intake also contribute.

The term is often used synonymously with “osteoporosis,” but the WHO defines it as a precursor stage.

The standard test is DXA (dual-energy X-ray absorptiometry). It is quick, painless, and measures bone density, usually in the lumbar spine and hip. Other methods can complement it.

  • Bone density measurement (DXA)
  • Blood tests (bone metabolism parameters)
  • Possibly X-rays of the spine
  • Detailed medical history (symptoms, medications, past illnesses, fall risk)

Yes. It can slow progression and strengthen bones.

Lifestyle adaptations include a calcium-rich diet, adequate vitamin D, and regular exercise such as hiking, walking, strength training, tennis, dancing, or skipping.

Medications that inhibit bone breakdown and increase bone strength. Mainly used in osteoporosis and cancer-related bone loss.

Calcium is the building block of bones. Vitamin D helps absorb calcium from the gut and incorporate it into bone. A deficiency increases fracture risk.

  • Bisphosphonates: slow bone breakdown, increase stability.
  • Osteoanabolic therapies (e.g., teriparatide): stimulate bone formation.
    Other options depend on individual risk, comorbidities, and tolerability.

Best are weight-bearing and impact activities:

  • Running, brisk walking, climbing stairs, dancing, jumping/skipping, strength training.
  • Balance training (e.g., tai chi, yoga, balance exercises) helps prevent falls.
  • Calcium: dairy, calcium-rich mineral water, green vegetables (broccoli, kale), nuts, tofu.
  • Vitamin D: fatty fish, egg yolk; also sunlight (moderately).
  • Vitamin K: leafy greens, legumes.
  • Eat a balanced diet with sufficient protein.

Falling estrogen levels accelerate bone loss in the first years after menopause, raising the risk of osteoporosis and fractures. Later, the rate of loss slows but continues. Women are therefore affected more often than men.

* Click to learn more