The main clinical syndromes

The clinical manifestations of hypothyroidism consist of the following main syndromes :

 I. Exchange hypothermic syndrome. Typical for hypothyroidism is a constant feeling of coldness, a decrease in body temperature, hyperlipoproteinemia (increased cholesterol and triglyceride levels), a moderate increase in body weight (due to a decrease in lipolysis and water retention).

Ii. Hypothyroid dermopathy and ectodermal disorder syndrome. The development of this syndrome is associated with impaired metabolism of glycaosaminoglycans in conditions of deficiency of thyroid hormones, resulting in an increase in tissue hydrophilicity. It is characterized by myxedematous swelling of the face and extremities, large lips and tongue with imprints of the teeth along the lateral edges, an “old-looking face” with coarse features. The skin is thick, dry, cold, pale with a yellowish tinge (due to a violation of the? -Carotene metabolism), does not fold, it peels off at the elbows. Hair is dull, brittle, falling on the head, eyebrows (Hertohe symptom), limbs, slowly growing. Sometimes there is a total alopecia, probably of an autoimmune nature. The nails are thin, with longitudinal or transverse striation.

  Iii. The defeat of the nervous system and sensory organs. The development of this syndrome is associated with inhibition of higher nervous activity and unconditioned reflexes in conditions of a lack of thyroid hormones. Characterized by inhibition, drowsiness, memory loss, hypomimia. Development of depressions, delirious states (myxedema delirium), paroxysms of panic attacks is possible. Many patients have sleep apnea syndrome. The most severe manifestation of central nervous system damage in hypothyroidism is hypothyroid coma (see below).

Symptoms of damage to the peripheral nervous system include paresthesia, slowing of tendon reflexes.

Detected and dysfunction of the sense organs: difficulty in nasal breathing (due to swelling of the nasal mucosa), hearing impairment (edema of the auditory tubes and organs of the middle ear). The voice of patients becomes low and rough (due to swelling and thickening of the vocal cords).

Iv. The defeat of the cardiovascular system. Changes in the cardiovascular system in hypothyroidism are associated with a decrease in the effect of thyroid hormones and catecholamines on the heart (the sensitivity of β-adrenoreceptors decreases), as well as the development of dystrophic changes in the myocardium. Characterized by bradycardia, decreased cardiac output, deafness of heart sounds. Many patients suffer from cardialgia, the occurrence of which is associated with myocardiodystrophy. Typical for hypothyroidism is considered low blood pressure with a decrease in pulse. At the same time, in a number of patients the pressure remains normal, and in some patients arterial hypertension is recorded (see below).

Characteristic changes in the ECG are sinus bradycardia, as well as a decrease in the voltage of the teeth. Changes in the end part of the ventricular complex are possible: depression of the S – T segment, reduction, biphasic or inversion of the T wave. Arrhythmias in hypothyroidism are very rare, but they can appear on the background of thyroid hormone replacement therapy.

One of the characteristic symptoms is the presence of fluid in the pericardium (detected in 30-80% of patients). The volume of pericardial effusion can vary: from minimal, detected only with ultrasound, to pronounced, leading to cardiomegaly and heart failure.

Although hypothyroidism is not considered a traditional risk factor for coronary artery disease, the nature of lipid metabolic disorders in these diseases is the same. Apparently, hyperlipidemia inherent in hypothyroidism may contribute to the acceleration of atherogenesis and the development of coronary artery disease.

  V. Changes in the gastrointestinal tract. They are manifested by constipation, biliary dyskinesia, decreased appetite. Often accompanied by autoimmune gastritis.

Vi.   Anemic syndrome. Hematopoietic disorders should be considered as one of the characteristic manifestations of hypothyroidism. Currently, it has been established that a deficiency of thyroid hormones leads to qualitative and quantitative disorders of erythropoiesis, that is, to the so-called thyroid-sensitive anemia. In its genesis, both the deficit of thyroid hormones per se and the decrease in the formation of erythropoietins are important. In addition, hypothyroidism is often observed B12 -deficiency and iron deficiency anemia, and hemolytic anemia may be associated with immune forms.

In addition to changes in the red sprout, platelet disorders are characteristic of hypothyroidism: their adhesive-aggregation function decreases, although the number remains within normal limits.

VII. Impaired kidney function. In hypothyroidism, a decrease in the renal blood flow and glomerular filtration rate is often observed, with the appearance of a small proteinuria.

Viii. Reproductive dysfunction. Women with hypothyroidism often have menstrual irregularities of the type of oligoopmenorrhea or amenorrhea, anovulatory cycles. In most cases, these disorders are combined with galactorrhea and are due to elevated levels of prolactin ( hyperprolactinemic hypogonadism syndrome, or persistent galactorrhoea-amenorrhea syndrome ). The presence of this syndrome in patients with primary hypothyroidism is known as Van Vick-Hennes-Ross syndrome ( more precisely: Hennes-Ross syndrome ).

The occurrence of hyperprolactinemia in primary hypothyroidism is associated with the action of hypothalamic thyrotropin-releasing hormone (TRH), the synthesis of which under conditions of deficiency of thyroid hormones multiplies by the mechanism of negative feedback. TRH is able to stimulate not only TSH secretion, but also prolactin. In addition, the development of hyperprolactinemia in hypothyroidism contributes to the deficiency of dopamine – the main hypothalamic inhibitor of prolactin secretion. Hyperprolactinemia leads to violations of the cyclical secretion of luteinizing hormone and the reception of gonadotropins in the gonads. Long-existing hyperprolactinemia contributes to the development of secondary polycystic ovarian disease.

The onset of pregnancy against decompensated hypothyroidism is extremely rare. In the event of pregnancy, in almost 50% of cases, it ends in spontaneous abortion.

In men, hyperprolactinemia in hypothyroidism is manifested by a decrease in libido and potency, impaired spermatogenesis.

Ix. The defeat of the musculoskeletal system. For hypothyroidism, a sharp (by a factor of 2-3) deceleration of bone remodeling processes is typical: both bone resorption and bone formation are inhibited. In women with untreated hypothyroidism, osteopenia (a moderately pronounced decrease in bone mineral density) is found.

In hypothyroidism, myopathies can develop with both muscle hypertrophy and atrophy.

The syndromes described above together form a characteristic clinical picture of a decrease in thyroid function.

local_offerevent_note December 16, 2019

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