The thyroid gland is a small, butterfly-shaped gland located in the front of the neck, just below the Adam’s apple. Although not very large in size, the thyroid gland plays a key role in the functioning of the body. This gland produces hormones that regulate the functioning of the whole body.

What are hormones?

Hormones are chemical messengers produced by the glands and released into the bloodstream. These hormones regulate various functions of the body, such as metabolism, growth, emotions, and body temperature. Hormones have a specific effect on each cell, tissue and organ in the body and help to maintain internal balance, called homeostasis.

Thyroid hormones:

The thyroid gland produces two main hormones:

1. Thyroxine (T4): this is the main hormone produced by the thyroid gland. Thyroxine affects almost every cell in the body and regulates the rate of metabolism, growth and development.
2. Triiodothyronine (T3): a portion of the hormone T4 is converted in various tissues of the body into T3, which is a more biologically active form. The hormone T3 directly affects metabolism, body temperature and many other bodily functions.

These hormones work together to ensure the normal functioning of the body and its ability to adapt to different environmental influences.

Main functions of the thyroid gland

1. Metabolic regulation: the thyroid gland’s most important function is to regulate metabolism. It produces two main hormones: triiodothyronine (T3) and thyroxine (T4). These hormones determine how quickly the body uses energy. If the thyroid gland produces too many hormones (hyperthyroidism), the metabolism speeds up, which can lead to weight loss, agitation and palpitations. If you produce too little hormone (hypothyroidism), your metabolism slows down, which can cause weight gain, fatigue and depression.
2. Growth and development: thyroid hormones play a key role in growth and development, especially in childhood. These hormones also affect the development of the brain and nervous system, so proper thyroid function is vital for normal physical and mental development.
3. Body temperature regulation: thyroid hormones help maintain body temperature. When the body is in a cool environment, the thyroid gland can produce more hormones to increase metabolism and keep the body warm.
4. Regulating heart rhythm: T3 and T4 hormones also affect the heart. These hormones help regulate heart rate and blood pressure. Changes in hormone levels have a direct effect on heart rate.
5. Muscle function and maintenance of energy levels: thyroid hormones, especially T3, play an essential role in normal muscle function and maintenance of energy levels. These hormones ensure that muscles get the right amount of energy when they need it, for example during physical activity. If the thyroid gland is not producing enough hormones, muscles can feel weak and tired, and a person’s overall energy levels can also decrease.
6. Digestive system function: thyroid hormones also affect the digestive system. The right amount of hormone helps normal bowel movements, which contributes to digestion and bowel movements. In hypothyroidism, constipation may often occur, while in hyperthyroidism, diarrhoea may also occur.
7. Mood and brain function: thyroid hormones have a direct effect on brain function, including mood and cognitive abilities. Hormone levels can affect a person’s emotional state, concentration, memory and general mental state. Depression and mental slowing are common in people with hypothyroidism, while hyperthyroidism can cause anxiety, nervousness and irritability.
8. Skin and hair health: thyroid hormones also affect skin and hair health. Normal hormone levels leave skin smooth and hydrated and hair healthy and strong. In hypothyroidism, the skin can become dry and rough, the hair can become brittle and hair loss can occur. With hyperthyroidism, the skin may become thinner and hair loss may occur less frequently.