Symptoms
An enlargement of the thyroid gland can initially occur completely without physical symptoms, or it can affect the metabolic state. The size of the thyroid gland therefore does not allow immediate conclusions to be drawn about its function. For this reason, hyperthyroidism (overproduction of thyroid hormones) and hypothyroidism (underproduction) can occur in cases of hyperthyroidism.
Of course, a completely normal, physiological production can also be present. Signs of hyperthyroidism are nervousness, restlessness, heavy sweating, weight loss with constant ravenous appetite, hair loss, rapid pulse, high blood pressure, diarrhea, to name but a few. Hypothyroidism is characterized by depressed mood, listlessness, weight gain, dry skin, hair loss, possibly rough voice, and constipation.
Usually not all symptoms are present at the same time, but only some of them. Hypothyroidism often turns into hyperthyroidism, and vice versa. This is due to the disturbed regulation of the thyroid hormones, which are then sometimes released too much, sometimes too little.
If there is a euthyroid metabolic condition, i.e. neither over- nor under-functioning of the thyroid gland, the enlargement of the thyroid gland is still physically noticeable: The excess tissue presses on the oesophagus and possibly the windpipe. Patients report symptoms, such as a strange feeling when swallowing, as if they had “a lump” in their throat.On the neck, a tissue enlargement is to be palpated, with varying degrees of intensity depending on the stage. In advanced stages there is also shortness of breath, especially during exercise. Wearing tight clothing, such as ties, is also uncomfortable, as the neck is additionally constricted. A stridor, i.e. a whistling sound when breathing in or out, can be an additional symptom.
Causes
The most common cause of thyroid enlargement is iodine deficiency. Since the thyroid gland needs iodine to produce its hormones, it reacts very sensitively to a lack of supply of this element. In case of a permanent iodine deficiency, the body carries out a very simple calculation: If 100 cells can only work halfway due to a lack of iodine, 200 cells are needed to produce the same amount of thyroid hormones.
This is of course a simplified example, in reality there are many more glandular cells, and the thyroid gland no longer functions exactly “halfway”. However, this example shows why the thyroid gland suddenly grows when iodine is deficient. Iodine deficiency was especially in earlier times a big problem in “iodine deficiency areas”.
Thus areas were and are called, in which the population cannot take up sufficient iodine with the food on natural way. Austria, for example, introduced a legal iodination of food, so that the iodine is inevitably absorbed with the food, and also iodine deficiency areas are supplied. Iodized table salt can also be bought in Germany.
Since the introduction of these measures, the number of struma operations has fallen sharply. In addition to iodine deficiency, which accounts for 90% of strumes, there are a number of other causes that can be responsible for thyroid enlargement: Tumors of the pituitary gland can lead to a constant release of too much of the thyroid stimulating hormone (TSH). TSH stimulates the thyroid gland to produce thyroid hormones.
If the thyroid gland is required to produce at a high rate over a long period of time, it must, so to speak, expand its capacity and become larger. This is what happens when too much TSH affects the thyroid gland. In addition, however, inflammation of the thyroid gland can also occur, which is known as “thyroiditis“.
Inflammation is always accompanied by swelling, so that in this case, too, a goiter is formed. Cysts and both benign and malignant tumors can also cause the thyroid tissue to swell. However, not only the body’s own processes can lead to an enlargement of the thyroid gland, but also externally administered drugs that are “strumigenic” – i.e. produce goiter – can play a role. These include lithium, thyrostatics, nitrates, and thiocyanate, among others. The list of possible causes is long, with iodine deficiency being the overwhelming majority (90%).