Which doctor treats the thyroid gland?

Since the thyroid gland is a hormone secreting gland, the doctor who knows best about the thyroid gland is the so-called endocrinologist. He is particularly concerned with hormones, their regulatory circuits and their glands. Under certain circumstances, the endocrinologist may commission a specialist in nuclear medicine to determine the hormone-producing activity of the tissue; the so-called thyroid scintigraphy. This is suitable for finding areas of the thyroid gland that may be overactive or no longer active. However, if there is a need to remove all or part of the thyroid gland, the general surgeon is the one who performs the surgery.

Thyroid hormones

The so-called thyroid hormones are triiodothyronine (T3) and thyroxine (T4). These differ in whether three (T3) or four (T4) iodine atoms are bound to the hormone molecule. Thyroid hormones have an effect on the entire body through their binding to special receptors.

In general, they have a metabolism-promoting and heat-generating (thermoregulatory) effect by increasing energy consumption and also increasing the breathing rate. They also have a stimulating effect on the heart, whereby the pulse and strength of the heart is increased to a certain extent. Also anabolic (anabolic) metabolic pathways, such as muscle building, are stimulated, although an overdose again has the opposite effect.

In the phase of child growth, they also play a major role in body and skeletal growth and also in the maturation of the nervous system. The thyroid hormones also have a stimulating effect on all other cells of the human body, e.g. on skin and hair or the gastrointestinal tract. This also results in the symptoms of a deficiency or an excess.

A deficiency, such as that which occurs in the case of hypothyroidism, can manifest itself, for example, in internal weakness, weight gain, sensitivity to cold (due to less heat production), a low pulse rate and dry, brittle skin. An excess, such as in hyperthyroidism, can manifest itself in an increased pulse, damp and sweaty skin, inner restlessness and nervousness. The thyroid gland produces and stores hormones bound to a carrier protein (thyroglobulin).

If required, these are then mobilized from the storage reserves and released into the bloodstream. Since thyroid hormones are poorly soluble in water, they are also bound in the blood to carrier and transport proteins (serum albumin, TBG, transthyretin). However, only those parts of the blood that are not bound are really hormonally active, whereby these make up the smallest part (less than 1%).

The release of the two thyroid hormones is not in equal proportions, but rather in a ratio of 20% T3 and 80% T4. Biologically really effective, however, is mainly the so-called T3. The T4 practically serves as an existing reserve, since the T3 is broken down much faster (T3 half-life: approx.

1 day, T4 half-life approx. 1 week). The T4 is then converted by certain enzymes, so-called deiodases, to the biologically more active T4.

The T3 can therefore be regarded as a kind of depot form of the T4. In laboratory tests, the so-called TSH is often determined as a replacement for the thyroid hormones. This laboratory value is good for estimating the body’s need and supply of thyroid hormones.

In 30% of the adults in Germany an oversized thyroid gland can be determined.Regardless of the cause of the thyroid enlargement, one then speaks of a goiter, colloquially also called “goitre”, but small nodes in the thyroid gland also occur. The enlargement can be very subtle, so that it can only be seen by ultrasound measurement or when the head is leaning back strongly, or even in a normal body position, and can cause swallowing difficulties. In extreme cases, the magnification can even constrict the windpipe located directly behind the thyroid gland and cause breathing difficulties.

If the enlargement is also painful, an additional inflammation of the thyroid gland (= thyroiditis) must often be considered. It is important to know that the size does not say anything about the hormone production. People with a large thyroid gland do not automatically have a large amount of thyroid hormones in their blood.

On the contrary, it is not uncommon for them to have an underactive thyroid gland. At 90%, iodine deficiency is the most common cause of the painlessly enlarged thyroid gland. The lack of iodine in the body is usually due to an iodine deficiency in the diet.

Iodine deficiency leads to a lack of thyroid hormones in the body, because iodine is a central component of these hormones. The thyroid gland, like many tissues in the body, reacts to this deficiency by growing its tissues to produce more effective hormones. However, this growth does not take place to the same extent in all parts of the thyroid gland, and it results in the formation of differently active areas, the “nodes”.

In the case of iodine deficiency, the administration of iodine tablets or, rarely, additional “finished” thyroid hormones often leads to a reduction in the size of the thyroid gland and the abnormally grown areas recede. In addition to iodine deficiency, autoimmune diseases are rarer causes of thyroid growth, such as Graves’ disease (=Basedow’s disease) or Hashimoto’s thyroiditis (named after the Japanese doctor Hashimoto). Here the body reacts to the thyroid gland tissue, because it no longer recognizes it as belonging to itself and attacks it.

This attack changes the metabolism of the thyroid gland and leads to the growth of all thyroid tissue. A cyst (fluid-filled cavity) or certain drugs (e.g. :lithium or nitrates) can also lead to enlargement. An enlarged thyroid gland must be clarified in detail in any case, since rarely a tumor can also be the cause of enlargement. Only when the exact cause of the enlargement is known can the correct treatment of the enlarged thyroid be started, which varies greatly depending on the cause.