Beginning >> Diseases >> Endocrine >> Hyperthyroidism

Endocrinology

Hyperthyroidism

Hyperthyroidism - the clinical state caused by abnormal work of a thyroid gland at which secretion of hormones of a thyroid gland (thyroxine and triiodothyronine) increases and it is not regulated by the gipotalamo-pituitary center.

Epidemiology.

The hyperthyroidism is more characteristic of women, than of men (a ratio 5:1). The general prevalence among all population makes about 1,3%, in a female age group 48 years – from 3 to 5% are more senior. On supervision of WHO at 15% of the population 60 years are more senior hyperthyroidism symptoms develop.

Etiology.

There are several reasons of development of a hyperthyroidism:

  • Greyvs's illness (a bazedova an illness, or a diffusion toxic craw) – the most frequent reason, is observed in 80% of cases of a hyperthyroidism. This autoimmune disease at which the immune system of an organism glitches and develops certain antibodies which, in turn, provoke hypersecretion of a thyroid gland. Among possible etiologies of Greyvs genetic predisposition, physical and emotional stresses, iodine overconsumption are considered. Usually develops at women at the age of 20-45 and has higher frequency among smokers.
  • High-quality new growths of a thyroid gland (a toxic multinodal craw - 15-20% of all cases, adenoma of a thyroid gland - 3-5%). Nodal growth on a thyroid gland often is followed by the increased hormonal activity of these educations (so-called "hot nodes").
  • Adenoma of a hypophysis possesses independent TTG the cosecreting activity.
  • Overconsumption of iodine with food leads to the increased synthesis of two most important hormones of a thyroid gland of thyroxine (T4) and triiodothyronine (T3). This reason is characteristic of places where in a diet of the population seafood prevails.
  • Artificial hyperthyroidism. Overdose of hormones of a thyroid gland can happen in two cases for a long time: at uncontrolled use of hormones for the purpose of weight loss or at overdose by replacement drugs in therapy of cancer of thyroid gland.
  • Side effect of drugs. Some drugs used at treatment of heart diseases contain a large amount of iodine. So, purpose of the drug "Amiodaronum" can bring to Amiodaronum - to the induced hyperthyroidism.
  • Thyroiditis, or inflammation of a thyroid gland. Most often results from virus infection. Especially allocate a puerperal thyroiditis.
  • Tumoral diseases of female generative organs. Trophoblastic tumors of a uterus and rare tumors of ovaries (struma ovarii) cosecrete TTG hormones.

Pathogeny.

Autoimmune disorders are the main of the pathogenetic reasons of a hyperthyroidism when G (IgG) immunoglobulins interact with the tissues of a thyroid gland producing development of TTG. This theory of genetically caused hyperthyroidism is the only hypothesis of a releaser of this disease today.
Excess production of hormones of a thyroid gland leads to increase in consumption by oxygen body tissues that involves acceleration of energy balance. In blood binding of sex hormones is observed, estrogen prevails over androgens. Excess of thyroid hormones quickly destroys cortisol that results in reversible adrenal insufficiency. At the cellular level protein synthesis therefore there are accruing pathological changes in work of many bodies and systems is broken.

Clinic, symptoms.

Weight of clinical manifestations of a hyperthyroidism and their complex combination varies from the person to the person and depends on hyperthyroidism degree (easy, average, heavy), duration of a disease, age of the patient and associated diseases. Patients with an easy form often have no external signs. The address to the doctor happens usually to emergence of symptoms of disturbance of a metabolism when acceleration of all exchange processes with considerable weight reduction is observed. The main symptomatology of a hyperthyroidism includes:

  • From the central nervous system: emotional lability, concern, nervousness, irritability, sleep disorders, decrease in memory, small wide tremor.
  • From warmly vascular system: the tachycardia which is badly giving in to treatment by drugs of cardiac glycosides and not passing at rest and a dream; there can be a ciliary arrhythmia of auricles, an otdyshka; tendency to big pulse pressure.
  • Vegetative symptoms: the increased perspiration, integuments to the touch warm and wet, is observed muscular weakness, sensitivity to heat.
  • From a digestive tract: the increased appetite is characteristic; various disturbances of a chair, diarrhea develops more often; sometimes vomiting, pains in an abdominal cavity; at a heavy hyperthyroidism – damages of a liver up to jaundice come to light.
  • From integuments: the hair loss, a skin itch with rashes (urticaria), nails become friable, hair become thinner and early turn gray.
  • Sexual sphere: both at women and at men the libido decreases; women have various disturbances of a menstrual cycle, infertility is frequent to an amenorrhea; at men the potentiality decreases and chest glands (gynecomastia) can bulk up.

At a palpation of outside part of a neck depending on primary disease evenly increased gland (a diffusion toxic craw) or nodular educations (a nodal toxic craw) is probed. The enlargement of the thyroid gland is distinguished on degrees:
1 degree. Hypostasis of gland is not visualized at external examination, the isthmus is palpated.
2 degree. Hypostasis is visualized when swallowing, at a palpation lateral shares are increased.
3 degree. Hypostasis of gland is visualized at external survey.
4 degree. Changes of contours of a neck are visible, the craw is observed.
5 degree. Craw of the big sizes.
The characteristic external sign – an ophthalmopathy, bilateral autoimmune damage of eyes at which hypostasis of periorbital fabrics develops and is bared a sclera. Externally it looks as a "angry" look, such state can develop at any form of a hyperthyroidism because of increase of an adrenergic tone. True ophthalmopathies arise in 50% of all cases of a hyperthyroidism, namely at Greyvs's illness.

Diagnosis.

The hyperthyroidism of average and heavy weight is quite simple for diagnosis. At early stages symptoms are not so obvious and the considerable number of patients remains without due medical consideration. The main symptoms of a disease are defined at poll of the patient and medical examination, for statement of the diagnosis blood tests on the level of hormones of a thyroid gland T3 and T4 are very indicative. Diagnostic scanning of a thyroid gland with use of a radioiodine is in certain cases carried out.

Treatment.

The choice of medical tactics depends on an etiological factor and degree of a hyperthyroidism, and also age and a condition of the patient. There are three main directions in treatment of a hyperthyroidism:
- conservative treatment;
- surgical treatment;
- treatment using a radioiodine (I-131).
Conservative treatment is carried out using anti-thyroid drugs (propylthiouracil, Methimazolum) and is directed to suppression of hypersecretion of a thyroid gland. Therapy is carried out not less than a year. Unfortunately, long remissions after treatment are observed only at 30% of patients, at the others - recurrence within two years after the conducted course.
Surgical treatment is chosen at inefficiency conservative or at threat of recurrence of a disease. Also it is preferred at contraindications to treatment by a radioiodine (at pregnancy and/or the big sizes of a craw). All gland is removed (thyroidectomy) at extent of increase 4-5 because of oncological vigilance, only the site with hyper secretory activity sometimes is removed. The surgical method is good fast achievement of medical effect and an absolute recovery of most of patients.
I-131 allows to reduce quickly synthesis of T3 and T4 of hormones, but in 8-15 days the medical effect vanishes (so-called "uskolzaniye") therefore it is applied at a preparation for surgery or at thyrocardiac crisis. The remote effects in the form of a hypothyroidism are possible.
Each method of treatment has the advantages and shortcomings, in many cases it is necessary to combine all three methods, also symptomatic treatment (antihistamines, cardiacs, tranquilizers, soothing drugs, etc.) is shown.

The forecast at a hyperthyroidism favorable, threat for life is posed by only critical states of thyrocardiac crisis.

 
"Giperprolaktinemiya   Hypoglycemia"