Hypothyroidism (synonyms: Hypothyroidism; hypothyroidism; cretinism; myxedema; hypothyroidism; ICD-10-GM E03.-: Other hypothyroidism) refers to hypothyroidism. The body no longer receives an adequate supply of the thyroid hormones triiodothyronine (T3) and thyroxine (T4). The main result is that metabolic processes in the body are slowed down and performance is reduced.
The cause of this dysfunction of the thyroid gland in children is a deficiency of iodine, which then leads to the picture of cretinism. It can lead to physical and mental developmental disorders.
Another cause, which mainly affects adults, is thyroiditis Hashimoto (autoimmune disease of the thyroid gland).
Hypothyroidism is the most common endocrine disease after diabetes mellitus.
In addition, hypothyroidism also plays a role as a secondary disease after thyroid surgery, such as thyroidectomy (surgical removal of the entire thyroid gland).
The following forms of hypothyroidism in adults are distinguished:
- Primary (thyrogenic) hypothyroidism [regulatory circuit in the thyroid gland is interrupted].
- Most commonly the result of an autoimmune disease such as Hashimoto’s thyroiditis
- Iatrogenically caused (caused by medical procedures) – after strumectomy (removal of thyroid tissue), after radioiodine therapy, drug-induced (e.g., thyrostatic drugs, lithium, sunitinib, amiodarone)
- Secondary pituitary hypothyroidism [regulatory circuit in the pituitary gland is interrupted, e.g., due to insufficiency/weakness of the anterior lobe of the pituitary gland]
- Tertiary hypothalamic hypothyroidism [default of the set point is absent due to TRH deficiency, e.g., in the context of damage to the hypothalamus, Pickardt syndrome, or euthyroid sick syndrome] (very rare)
Sex ratio: males to females is 1: 4.
Frequency peak: autoimmune hypothyroidism occurs predominantly after the age of 60.
The prevalence (frequency of disease) is 1% (in Germany).
The incidence (frequency of new cases) of autoimmune hypothyroidism is approximately 4 cases per 1,000 population per year in women and 1 case per 1,000 population per year in men (in Germany). The incidence for connatal (congenital) hypothyroidism is 1 disease per 3,000-5,000 newborns per year. The incidence in childhood and adolescence for hypothyroidism in Hashimoto’s thyroiditis is 0.5 disease per 1,000 population per year.The incidence in childhood and adolescence for hyperthyroidism in Graves’ disease is 1 disease per 100,000 population per year.
Course and prognosis:Hashimoto’s thyroiditis often affects patients who are symptom-free for a long time. The diagnosis is often only made in the course of a goiter diagnosis or very late in the case of manifest hypothyroidism.Hypothyroidism is easily treatable. As a rule, those affected must substitute the thyroid hormone T4 for the rest of their lives. Many patients develop early atherosclerosis (arteriosclerosis, hardening of the arteries) over time. In case of permanent hypothyroid state, stress events (e.g. infections, surgery accident) or intake of substances that can lead to hypoventilation (opiates, narcotics, sedatives, alcohol), i.e. restricted lung ventilation, there is a risk of hypothyroid coma (myxedema coma; very rare).The mortality rate (death rate) of myxedema coma could be reduced to 20-25% thanks to intensive care medicine.
Comorbidities (concomitant diseases): Hypothyroidism is associated (linked) with a 1.5-fold risk of gout in men. Furthermore, untreated hypothyroidism is associated with depression and anxiety disorders.
