A 45-year-old woman visits her physician with complaints of fatigue,heat intolerance,goiter,and unusual hair loss.Blood is collected and serum T₄ value is below the healthy reference interval.What laboratory assay would confirm that this might be a pituitary disorder?

Question

Quizplus · Accepted Answer

Thyroid-stimulating hormone (TSH) is produced by the pituitary gland and stimulates the thyroid gland to produce thyroid hormones. In cases of primary hypothyroidism (where the thyroid gland is not functioning properly), TSH levels increase as the pituitary gland attempts to compensate for the lack of thyroid hormones. However, in secondary hypothyroidism (where the problem is with the pituitary gland), TSH levels will be low despite low levels of thyroid hormones in the blood. Therefore, in this case, measuring TSH levels would confirm whether the hypothyroidism is due to a pituitary disorder.

A 45-Year-Old Woman Visits Her Physician with Complaints of Fatigue,heat