Hyperthyroidism

An overactive thyroid is also known in the medical terminology as hyperthyroidism. It is a disease that is associated with an increased production of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The prevalence of hyperthyroidism is 2-3% of the total population.In Germany, the most common causes are the autoimmune disease Graves’ disease or a functional autonomy of the thyroid gland.

Between the ages of 20 and 40, Graves’ disease is considered the most common trigger of hyperthyroidism, whereas functional autonomy is considered the most common trigger of thyroid disease from the age of 50. The symptoms of hyperthyroidism are very diverse. Increased hormone production has a particular effect on the metabolism and circulation, but it also affects psychological well-being and growth.

Patients generally often complain of nervousness, restlessness, insomnia, increased sweating and weight loss. In addition, hair loss, increased appetite and thirst, an increased stool frequency with possibly diarrhoea and muscle complaints (myopathy) can occur. In rare cases, male patients with hyperthyroidism may develop gynecomastia (enlargement of the mammary gland); women also complain of menstrual disorders.

A characteristic finding of immunologically induced hyperthyroidism is pretibial myxedema (=distension of the skin on the shin bone due to the accumulation of glycosaminoglycans). The therapeutic treatment of hyperthyroidism is usually carried out with so-called thyrostatic drugs. These drugs inhibit the new synthesis of thyroid hormones through various mechanisms with the aim of achieving euthyroidism (= normal thyroid production).

Hyperthyroidism can also be treated surgically. The prerequisite, however, is the euthyrotic metabolic state prior to the start of the operation using thyrostatic drugs. Subsequent follow-up treatment with L-thyroxine is mandatory, since partial resection (removal of certain parts) of the thyroid gland can lead to hypothyroidism, i.e. underfunction.

A frequent undesirable complication during surgery is the injury to the laryngeal recurrens nerve (recurrent paresis), since this is closely related topographically to the thyroid gland. Nodules in the thyroid gland can be detected in more than 50% of the population and the percentage increases with age. According to studies, a nodule can be detected in every second adult from the age of 65.

Nodules can be cysts (fluid-filled cavities), growths, scarring and calcifications as well as hormone-producing changes in thyroid tissue. In medical terminology, a distinction is made between “cold”, “warm” and “hot” nodules with regard to the hormone-producing nodes. However, the term cold, warm or hot does not refer to the temperature of the node, but to its activity, i.e. whether it is busy producing hormones or not.

This hormone production can be measured by means of the so-called scintigraphy. This involves creating a colorful image of the thyroid gland using different colors. The activity of the area determines which color it is shown in the image.

Thus, the colors of hot, very active areas change to warm tones such as red and yellow and to cold colors such as blue and green with reduced activity. Behind such an area of a cold node is often a simple tissue change that is no longer able to produce hormones. These can be cysts (fluid-filled cavities), adenomas (benign proliferation of the hormone-producing cells), calcifications or scars in the tissue.

In rare cases (max. 5%), however, a malignant tumor may also be behind it. In advance, rapid growth and a coarse, unchanging consistency may indicate malignant growth.

A cold lump must always be treated due to this rare cause. A final diagnosis can be made by fine needle puncture, an uncomplicated way of biopsy. Here, a small tissue sample is taken through a thin needle and examined under a microscope.

Depending on whether the change is then good or malignant, the treatment procedure varies from observation through regular ultrasound checks to complete removal of the thyroid gland. Radioiodine therapy is not effective for cold nodules. As the procedure is based on the absorption of radioactive iodine by the cells and these nodules absorb little iodine, the cells cannot be combated in this way and the therapy cannot have any effect.