Hypothyroidism is a pathology, which is caused by a sharp lack or complete absence of thyroid hormones. As a rule, it develops against the background of complete dysfunction of this endocrine organ. Important: according to medical statistics, hypothyroidism has become almost the most common pathology among all endocrine diseases. It is exposed to the majority of women who have reached the age of 65, as well as persons living at a great distance from the sea (i.e., in areas where the air is less iodized).
The most common disease of the thyroid gland is hypothyroidism, which is the result of chronic autoimmune thyroiditis, as well as iatrogenic hypothyroidism (postoperative, in the outcome of radioactive 131I therapy). Iatrogenic hypothyroidism accounts for at least 1/3 of all cases of hypothyroidism. With these diseases, hypothyroidism in most cases is persistent irreversible.
Along with this, for many diseases of the thyroid gland (destructive thyroiditis), as well as under the influence of a number of substances (large doses of iodine, thyreostatics), transient hypothyroidism may develop, which is self-limiting either in the course of the natural treatment of these diseases, or at the cessation of the effect of the factor that caused it (abolition thyreostatics). In some cases, the genesis of primary hypothyroidism remains unclear (idiopathic hypothyroidism).
One of the causes of primary hypothyroidism can be severe iodine deficiency. Light and moderate iodine deficiency to hypothyroidism in adults under normal conditions can not lead. In neonates due to moderate, and sometimes even mild iodine deficiency, due to a combination of low iodine content in the thyroid gland and a high level of thyroid hormone metabolism, transient neonatal hyperthyrotropinemia can develop. In pregnant women in conditions of iodine deficiency, relative gestational hypothyroxinemia may develop. Nevertheless, the last two phenomena should not be identified with hypothyroidism in full.
The reason for the relatively rare secondary hypothyroidism, as a rule, are various destructive processes in the hypothalamic-pituitary region. Most often we are talking about macroadenomas of the pituitary gland and suprasellar structures, as well as surgical interventions for these diseases.
The clinical picture of hypothyroidism is determined by its etiology, the age of the patient, and the rate of development of thyroid hormone deficiency.
The main problems of clinical diagnosis of hypothyroidism are:
As indicated, the clinical picture of hypothyroidism as a whole is characterized by polysystemic nature, but individual patients are dominated by complaints and symptoms from a single system, and therefore the patient is often diagnosed as a “mask” disease.
With a pronounced and long-lasting hypothyroidism, the patient has a rather typical “myxedematous” appearance, which is characterized by general and periorbital edema. The face is puffy, pale icteric, the look is alienated, the facial expression is poor (masklike face).
In addition, there is a thinning and dulling of hair, their increased loss. In general, patients are apathetic, slowed down or even inhibited. For severe hypothyroidism, speech retardation is very characteristic; Sometimes it seems that the patient has something in his mouth (the tongue is braided). The swelling of the laryngeal mucosa is manifested by a low or even hoarse voice. The patient can stumble on the pronunciation of individual words, after which, putting some effort, pronounces them more clearly. Classically, hypothyroidism describes the swelling of the tongue, on which you can see the prints of the teeth. The swelling of the mucous membrane of the Eustachian tube may be manifested by a slight decrease in hearing. A frequent complaint is dry skin.
Among the changes on the part of the nervous system, one should point out a decrease in memory and intelligence, drowsiness, depression. In children older than 3 years and in adults, changes in the nervous system are not irreversible and completely stop with substitution therapy. In contrast, congenital hypothyroidism in the absence of substitution therapy leads to irreversible neuropsychiatric and physical disorders. From the side of the peripheral nervous system, changes are rare, although in some patients, myxedema causes the development of tunnel syndromes (carpal tunnel syndrome).
A general decrease in the level of basal metabolism is manifested by a certain tendency of patients with hypothyroidism to gain weight, while actually hypothyroidism never leads to the development of pronounced obesity. With extremely severe hypothyroidism, hypothermia can develop. Patients often complain for chilliness (they get cold all the time). In the genesis of this symptom, along with a decrease in basal metabolism, the centralization of the circulation is characteristic of hypothyroidism.
The most frequent changes in the cardiovascular system are a tendency to bradycardia, mild diastolic arterial hypertension and the formation of effusion in the pericardial cavity. Most patients with hypothyroidism develop atherogenic dyslipidemia. On the part of the digestive system, constipation is a common symptom. In addition, dyskinesia of the biliary tract, hepatomegaly can develop; characterized by a slight decrease in appetite. With expressed hypothyroidism, hypochromic anemia can develop.
Very often, especially in women, the changes on the part of the reproductive system come to the forefront. When hypothyroidism can occur various disorders of the menstrual cycle: from amenorrhea to dysfunctional uterine bleeding. Both in men and women, there is a decrease in libido. In the pathogenesis of changes on the part of the reproductive system, secondary hyperprolactinemia plays a certain role. Expressed hypothyroidism is almost always accompanied by infertility, but less obvious deficiency of thyroid hormones in some women (about 2% among all pregnant women) may not interfere with the onset of pregnancy, which in this case is accompanied by a high risk of interruption or birth of a child with developmental disorders of the nervous system.
With the long-term hypothyroidism, hyperstimulation of thyroid pituitary thyrotrophins can result in the formation of a secondary adenoma. After compensating for hypothyroidism on the background of replacement therapy, as a result of a decrease in the volume of the pituitary gland.
Women on a background of hypothyroidism usually experience changes in the whole body, including the menstrual cycle, which threatens early menopause, infertility or miscarriages. In addition, the skin looks dry and wrinkled, often the condition of the hair worsens very much, and the constant apathy and inhibition leads to deep neuroses.
Danger of the disease in children, as long-term hypothyroidism without treatment leads to irrecoverable changes in the child’s body: stunting, mental disorders. And in the elderly, a hypothyroid coma may occur, which, without the rapid provision of adequate medical care, leads to death. In men, the risks are even greater, since hypothyroidism is less pronounced in them, and they even tend to write off the decrease in potency for other reasons, while the disease progresses.