Myxedema (redirected from pituitary myxedema)

myxedema (mĭksədē`mə), condition associated with severe hypothyroidism and lack of thyroid hormone in the adult. In the child it is known as cretinism. Symptoms include a dry swelling of the skin, slowed speech and mental awareness, deepened voice, intolerance to cold, fatigue and weakness, and nonspecific degeneration of the heart. Most cases result from atrophy of the thyroid from unknown causes, although surgical removal or irradiation of the gland also precipitates the disorder. Myxedema is treated by administering synthetic preparations of thyroxine (thryoid hormone), liothyronine (triiiodothyronine), a combination of the two synthetic hormones, and desicated animal thyroid.

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myxedema

Physiological reaction to low levels of thyroid hormone in adults, either due to thyroid-gland removal, lack of function, or atrophy, or secondary to a pituitary-gland disorder. Gradual changes include enlarged tongue, thick, puffy skin, drowsiness, cardiac enlargement, and slow metabolism. Low thyroid hormone affects levels of other hormones, and may result in low blood sodium and disorders of the reproductive system (including reduced fertility), adrenal glands, and circulatory system. Treatment is with thyroid hormone.

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myxoedema (US), myxedema

a disease resulting from underactivity of the thyroid gland characterized by puffy eyes, face, and hands and mental sluggishness

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myxedema [‚miks·ə′dē·mə]

(medicine)

A condition caused by hypothyroidism characterized by a subnormal basal metabolic rate, dry coarse hair, loss of hair, mental dullness, anemia, and slowed reflexes.

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Myxedema 

a disease caused by thyroid insufficiency (hypothyroidism) or complete thyroid failure. Thyroid and hypothalamic-pituitary myxedema are differentiated.

Thyroid myxedema may be congenital—resulting from abnormal intrauterine development, toxicoses of pregnancy, or intrauterine infection (syphilis, viral infections)—or acquired—resulting from injury or acute or chronic inflammation of the thyroid gland. This form of myxedema may also result from an autoimmune reaction against the body’s own thyroglobulin. Hypothalamic-pituitary myxedema is due to functional and organic changes that interfere with the production of the TSH-releasing factor of the hypothalamus or the thyrotropic hormone of the pituitary.

The main symptoms of myxedema are mucous edema of the skin and subcutaneous tissue, dry skin, sluggishness, drowsiness, poor memory, physical and mental lassitude, lowered basal metabolism, constant sensitivity to cold, lowered blood pressure, slow pulse, and intestinal sluggishness causing constipation. Myxedematous children suffer from dwarfism, slow bone growth, late eruption of the teeth, brittleness of nails, and mental disorders. Treatment includes the regular administration of thyroid preparations (thyroidin) and triiodothyronine.

REFERENCES

Baranov, V. G. Bolezni endokrinnoi sistemy i obmena veshchestv. [Leningrad] 1955.
Tareev, E. M. Vnutrennie bolezni, 3rd ed. Moscow, 1957.
Mnogotomnoe rukovodstvo po patologicheskoi fiziologii, vol. 4. Moscow [1966]. Pages 228–29.

L. M. GOL’BER