Hypothyroidism can occur not only due to pathological processes in the thyroid gland The thyroid gland - is responsible for your hormones . A large group of Hypothyroidism can be caused by diseases of the system that regulates the function of the thyroid gland. This regulatory system is located in the area of ​​the brain.

Hypothalamic-pituitary system, and secondary causes of hypothyroidism

The work of the thyroid gland is regulated by a complex neurohumoral mechanism called the hypothalamic-pituitary system. This system interacts with the thyroid gland, stimulating its activity. The main regulator of the activity of the thyroid gland is tireotoropny hormone (TSH), which is allocated the main internal secretion by the pituitary gland located in the brain. If the thyroid gland produces insufficient amount of their hormones (thyroxine - and triiodothyronine T3 - T4), the amount of TSH is increased if the same amount of T3 and T4 are too many, it decreases the amount of TSH.

In turn, TSH is also under control. This control is carried out by the hypothalamus (part of the brain responsible for the operation of the whole endocrine system) through its hormone secretion - tireotropinrilizing hypothalamic-releasing hormone (TRH).

In secondary hypothyroidism, thyroid-stimulating hormone content in the blood is reduced or normal in combination with reduced T4 (while in primary hypothyroidism Primary hypothyroidism: replacement therapy can help   TSH level will be raised, and T3 and T4 normal or low)

Causes of secondary hypothyroidism - the defeat of the hypothalamus or pituitary gland. It may be, injuries and their consequences, acute infection and intoxication, which can also have consequences in the form of changes in the brain tissue, tumors of the hypothalamus or pituitary, brain tumors, violate the venous circulation in the pituitary dysfunction of the adrenal glands, congenital malformations of brain the brain, the effects of radiation and chemotherapy of various tumors, the effects of necrosis (tissue death), the anterior pituitary gland in the massive blood loss.

Signs of secondary hypothyroidism

Signs of primary and secondary hypothyroidism are similar, but secondary hypothyroidism is characterized in that it proceeds more smoothly, because even with a lack of stimulation by the thyroid gland regulates the system still generates a certain amount of their hormones.

However, the secondary hypothyroidism has the features:

• paleness, easy yellowness and mucosal swelling of the skin, loss of hair on the head and on the outside of the eyebrows, brittle nails;
• swelling of the mucous membrane of the respiratory tract, and as a result - frequent inflammatory diseases, decreased lung capacity;
• frequent or, alternatively, occasional palpitations, cardiac arrhythmias, changes in blood pressure;
• large, do not put in the mouth tongue weakening of taste, loss of appetite, disturbance of locomotor activity of the muscles of the digestive system and bile ducts, which can lead to constipation, flatulence, stagnation of bile;
• decreased kidney function;
• menstrual irregularities, decreased sex drive;
• children - the backlog of passport bone age, growth retardation; adults - effects of osteoporosis (loss of bone calcium)
• iron deficiency anemia, blood clotting problems;
• decreased intelligence and memory, lethargy, inactivity, constantly in a bad mood;
• low body temperature, obesity, high blood cholesterol;
• hearing loss, hoarseness, difficulty in nasal breathing.

Diagnosis of secondary hypothyroidism

For the diagnosis of secondary hypothyroidism about the complete examination of the patient: thyroid ultrasound, isotope scintigraphy, thyroid needle biopsy (tissue taken for analysis by a puncture), the determination of antibodies against the thyroid tissue. Nevertheless, the main diagnostic criterion is the determination of TSH, T3 and T4 in the patient's blood.

For the availability of secondary hypothyroidism says sustained reduction in thyroid-stimulating hormone and thyroid hormones.

Treatment of secondary hypothyroidism

It is treated primarily a disease of the central nervous system caused by the condition of hypothyroidism. The tumors are removed, state after injuries and illnesses are treated conservatively.

At the same time the patient is prescribed replacement therapy in the form of thyroid hormone Thyroid hormones: mechanism of action and physiological effects . Today, this purpose is most often applied a L-thyroxine Thyroxine - the main thyroid hormone Which is easy to use (it is sufficient to take once a day) or cause side effects. The dosage of this drug is to choose a doctor as an overdose is fraught with serious complications of the cardiovascular system.

Galina Romanenko

The appearance of patients with hypothyroidism is very typical: round face, indifferent, slow motion, his face pale and puffy, sometimes with a slight bluish glow. The skin of patients with hypothyroidism, dry, flaky, brittle nails, hair is sparse. Experienced doctors diagnosed hypothyroidism before laboratory testing.

The main symptoms of hypothyroidism

Hypothyroidism usually develops gradually. Patients often do not notice symptoms for long periods of the disease and do not go to the doctor, they often complain of lethargy, reluctance to move, sudden memory impairment, drowsiness, edema, dry skin, and constipation.

The appearance of patients is changing, movement is slow, indifferent eyes, round face, puffy, swollen, especially in the lower eyelids, lips cyanotic, pale face slightly flushed well with a bluish tint. Patients in freezing weather. The skin is pale, sometimes with yellowish tinge because of the increased amount of carotene in the blood, cold to the touch, dry, rough, thickened, scaly. Peeling of the skin is often most pronounced in the front of the leg. Characteristically excessive actinic and thickening of the surface layers of the skin on the knees and elbows (symptom Bera).

There is swelling of the mucous skin. When pressed on the skin swelling of the place is not going to fold. Swelling often extends to language and nasal mucosa, and therefore may have voice disorders (hoarse voice).

Hair grows slowly, they are fragile, easily fall out. Often baldness occurs. Sometimes hair falls out of the outer third of the eyebrows. Brittle nails, with transverse and longitudinal grooves. The body temperature is lowered, many patients.

The thyroid gland in primary hypothyroidism is usually not detectable, the secondary can be a normal size.

Cardio-vascular system in the majority of patients have bradycardia (slow heart rate), reduction in circulating blood volume, expanding the boundaries of the heart. The pericardial cavity (the outer shell of the heart) is often accumulated mucous fluid. Systolic blood pressure (upper figure) is usually slightly reduced and diastolic (lower figure) - normal or slightly increased, thereby reducing pulse pressure. In connection with the violation of lipid metabolism, there are phenomena of atherosclerosis in blood vessels atherosclerotic plaques are deposited.

Patients often complain of loss of appetite, bloating, and constipation. Changes secretory and motor activity of the stomach, disrupted the process of absorption of food. Gradually decreases the filtration capacity of the kidneys.

Changes in other endocrine glands and metabolism in hypothyroidism

The function of the adrenal cortex in hypothyroidism varies slightly, but due to the sustained collapse of the hormones found in the urine reduced allocation of 17 - ketosteroids (hormones decay products).

Gonadal function decreases, the women may have uterine bleeding, amenorrhea sometimes appears The absence of menstruation (amenorrhea) - ambiguous symptom   (absence of menstruation).

Basal metabolism is lowered, in the blood reduces the number of red blood cells, iron deficiency anemia occurs. Patients with anemia and reduced white blood cell count, decreased the number of thyroxine Thyroxine - the main thyroid hormone , Triiodothyronine, iodine, bound to plasma proteins, increases the amount of cholesterol.

Moreover, in primary hypothyroidism significantly elevated titers of circulating thyroid autoantibodies (they are directed to the cell body of the patient). In secondary hypothyroidism, such as antibodies few or non-existent. It increases the body's ability to thrombosis.

The changes in the nervous system in hypothyroidism

In hypothyroidism changes occur in both the central and peripheral nervous system. They are characterized by disorders of the nervous-mental functions of organic type.

In mild cases of hypothyroidism can be observed only slowness of thought and speech, memory loss, fatigue. Patients are inhibited and have a peculiar appearance - puffy round face.

In hypothyroidism moderate severity is marked apathy, indifference, such patients rarely laugh or cry. Sometimes there may be irritability Irritability - you try to control my temper , Grudgingly, depressed mood and depression.

In marked hypothyroid dementia patients emotionally stupid, indifferent to others or monotone good-natured, but can be spiteful and unfriendly.

Against the background of chronic mental changes may occur psychosis-like psychosis in such mental illnesses Mental illness - ashamed to ask for help? As manic-depressive illness and schizophrenia. There are also seizures.

Symptoms of hypothyroidism develop gradually and it would be better to detect them at an early stage of the disease.

Galina Romanenko