Methods of endocrine system research

Manifestations of endocrine gland diseases are very diverse and can be detected already during a traditional clinical examination of the patient. Only the thyroid gland and testicles are accessible for direct examination (inspection, palpation). Laboratory studies currently allow us to determine the content of most hormonal substances in the blood, but the nature of metabolic disorders associated with changes in the content of these hormones can also be determined using special methods. For example, in diabetes mellitus, determining the glucose content in the blood often reflects metabolic disorders more accurately than the level of insulin itself, which controls glucose metabolism.

In diagnosing endocrinopathies, it is important to focus primarily on the diverse symptoms from various organs and systems - skin, cardiovascular system, gastrointestinal tract, musculoskeletal and excretory systems, nervous system, eyes, comparing them with the data of biochemical and other additional studies. It should be borne in mind that individual clinical manifestations of the disease may be due to differences and uneven distribution in tissues of receptors with which hormones interact.

Collection of anamnesis

When interviewing a patient, it is possible to identify a number of important data indicating dysfunctions of certain endocrine glands, the time and causes of their occurrence, and the dynamics of development.

Already at the beginning of the conversation with the patient, certain features can be quite clearly detected: hasty, incoherent speech, some fussiness in movements, increased emotionality, characteristic of hyperfunction of the thyroid gland, and, conversely, lethargy, apathy, some inhibition with its hypofunction.

Complaints. Complaints of patients with endocrine disorders are often general in nature (poor sleep, rapid fatigue, easy excitability, weight loss), but can also be more characteristic of damage to the corresponding endocrine gland, including they can be associated with the involvement of various organs and systems in the process (due to metabolic and hormonal disorders).

Patients may complain of skin itching (diabetes mellitus, hyperthyroidism), hair loss (thyroiditis), joint pain (acromegaly) and bones (hyperparathyroidism), bone fractures (hyperparathyroidism, Itsenko-Cushing syndrome), muscle weakness (Itsenko-Cushing syndrome, hyperaldosteronism), pain in the heart, palpitations with atrial tachyarrhythmia (hyperthyroidism, pheochromocytoma). Often there are complaints of poor appetite, dyspeptic phenomena (hypothyroidism, adrenal insufficiency), sexual dysfunction - amenorrhea (hyperthyroidism, hypogonadism, Itsenko-Cushing syndrome), menorrhagia (hypothyroidism), impotence (diabetes mellitus, hypogonadism).

Physical methods of studying the endocrine system

Inspection and palpation

As already noted, only the thyroid gland and testicles are accessible for inspection and palpation. However, it is very important in these cases, and in cases of damage to other endocrine glands (which cannot be inspected and palpated), to rely on the results of a physical examination of various organs and systems (skin, subcutaneous fat, cardiovascular system, etc.).

A general examination can already reveal a number of significant signs of endocrine system pathology: changes in growth (dwarfism while maintaining the proportionality of the body of pituitary origin, gigantic growth with increased pituitary function), disproportionate sizes of individual body parts (acromegaly), features of the hairline characteristic of many endocrinopathies, and a large number of other symptoms.

When examining the neck area, an approximate idea of the size of the thyroid gland, symmetrical or asymmetrical enlargement of its various sections is formed. When palpating the lobes and isthmus of the thyroid gland, the size, consistency, and nature (diffuse or nodular) of the enlargement are assessed. The mobility of the gland when swallowing, the presence or absence of pain and pulsation in its area are assessed. To palpate the nodes located behind the upper part of the sternum, it is necessary to immerse the fingers of the hand behind the sternum and try to determine the pole of the node.

When examining the skin, hirsutism (ovarian pathology, hypercorticism), hyperhidrosis (hyperthyroidism), hyperpigmentation (hypercorticism), ecchymosis (hypercorticism), purple-bluish striae - peculiar areas (stripes) of atrophy and stretching usually on the lateral parts of the abdomen (hypercorticism) are sometimes detected.

An examination of subcutaneous fat reveals both excessive development of subcutaneous fat - obesity (diabetes mellitus) and significant weight loss (hyperthyroidism, diabetes mellitus, adrenal insufficiency). With hypercorticism, excessive fat deposition is observed on the face, which gives it a moon-shaped rounded appearance (Itsenko-Cushing syndrome). Peculiar dense swelling of the legs, the so-called mucous edema, is observed with hypothyroidism (myxedema).

Examination of the eyes may reveal characteristic exophthalmos (hyperthyroidism), as well as periorbital edema (hypothyroidism). Diplopia may develop (hyperthyroidism, diabetes mellitus).

Important data can be obtained by examining the cardiovascular system. With a long course of some endocrine diseases, heart failure develops with typical signs of edema syndrome (hyperthyroidism). One of the important causes of arterial hypertension are endocrine diseases (pheochromocytoma, Itsenko-Cushing syndrome, hyperaldosteronism, hypothyroidism). Orthostatic hypotension (adrenal insufficiency) is observed less often. It is important to know that with most endocrine diseases, such changes in the electrocardiogram are observed due to myocardial dystrophy as rhythm disorders, repolarization disorders - shift of the ST segment, T wave. Pericardial effusion (myxedema) can occasionally be detected during echocardiography.

Sometimes a full complex of symptoms of malabsorption develops with typical diarrhea and corresponding laboratory changes, such as anemia, electrolyte disturbances, etc. (hyperthyroidism, adrenal insufficiency).

Urinary disorders with polyuria characteristic of diabetes mellitus against the background of polydipsia are often missed by both patients and doctors. Urolithiasis with renal colic symptoms occurs in hyperparathyroidism and Itsenko-Cushing syndrome.

When examining the nervous system, nervousness (thyrotoxicosis), rapid fatigue (adrenal insufficiency, hypoglycemia) are revealed. Impaired consciousness up to the development of coma is possible (for example, hyperglycemic and hypoglycemic coma in diabetes mellitus). Tetany with convulsions is characteristic of hypocalcemia.

Additional methods of research of the endocrine system

Visualization of endocrine glands is achieved by various methods. Conventional X-ray examination is considered less informative. Modern ultrasound examination is more informative. The most accurate picture can be obtained by computed tomography, X-ray or magnetic resonance imaging. The latter study is especially valuable in examining the pituitary gland, thymus, adrenal glands, parathyroid glands, and pancreas. These studies are primarily used to detect tumors of the corresponding endocrine glands.

Radioisotope examination of various endocrine glands has become widespread, primarily the thyroid gland. It allows for clarification of structural features (size), as well as functional disorders. The most widely used are iodine-131 or pertechnetate labeled with technetium-99. Using a gamma camera, gamma radiation is recorded on light-sensitive paper, and thus scanning occurs, which allows for evaluation of the size, shape, and areas of the gland that actively accumulate isotopes (the so-called hot nodes). Radioisotope scanning is used in the study of the adrenal glands.

There are various methods for determining the hormone content in the blood. Among them, the most noteworthy is the radioimmunoassay (RIA). Its principle is as follows: antibodies (antiserum) are prepared in advance for the substance being tested, which is an antigen, then a standard amount of the resulting antiserum is mixed with a standard amount of the original antigen labeled with radioactive iodine-125 or iodine-131 (up to 80% of the labeled antigen binds to the antibodies, forming a radioactive precipitate with a certain radioactivity). Blood serum containing the substance being tested is added to this mixture: the added antigen competes with the labeled antigen, displacing it from complexes with antibodies. The more of the substance being determined (hormone) is contained in the sample being tested, the more radioactive labels are displaced from the complex with the antibody. Next, the antigen-antibody complex is separated by precipitation or selective absorption from the free labeled hormone and its radioactivity (i.e. quantity) is measured in a gamma counter. The radioactivity of the precipitate decreases. The more antigen in the sample being examined, the less radioactivity the remaining precipitate has. This method can be used to detect small amounts of insulin, pituitary tropic hormones, thyroglobulin and other hormones in the blood and urine with great accuracy. However, it should be borne in mind that the increase in hormone content in the blood can occur due to their fraction associated with proteins. In addition, the radioimmune method allows for a quantitative assessment of substances that are chemically very similar to hormones, lacking hormonal activity but having an antigen structure common to hormones. Of some importance is the determination of hormone content after special load tests, which allow the reserve function of the gland to be assessed.

Among the biochemical blood tests, the most important is the determination of glucose content in the blood and urine, which reflects the course of the pathological process in diabetes mellitus. A decrease or increase in the level of cholesterol in the blood is characteristic of a dysfunction of the thyroid gland. Changes in calcium metabolism are detected in pathology of the parathyroid glands.

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