Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?
A) greater production of T₃ than of T₄
B) hyposecretion of thyroid-stimulating hormone (TSH)
C) hypersecretion of thyrotropin-releasing hormone (TRH)
D) a decrease in the thyroid secretion of calcitonin

Question

Quizplus · Accepted Answer

Hypothyroidism is most commonly caused by hyposecretion of thyroid hormones due to a variety of factors including autoimmune diseases, iodine deficiency, congenital anomalies, medications, and pituitary or hypothalamic dysfunction. However, if the patient's iodine level is normal, iodine deficiency is unlikely to be the cause. In this scenario, the most likely explanation for hypothyroidism is a problem with the regulation of thyroid hormone production, possibly due to a lack of stimulation from thyroid-stimulating hormone (TSH) produced by the pituitary gland. Therefore, choice B is the best answer. Choices A, C, and D are not correct because they do not relate to the regulation of thyroid hormone production.

Which of the Following Is the Most Likely Explanation for Hypothyroidism