If a patient's thyroid hormone (T4) levels are chronically elevated due to a thyroid tumor unresponsive to normal feedback loops, which consequence follows?

💡 Explanation

Chronically elevated T4, independent of hypothalamic-pituitary control, leads to sustained suppression of both TRH and TSH via negative feedback. Because the high T4 inhibits TRH release from the hypothalamus and TSH from the pituitary, therefore levels of both hormones decrease, rather than increase.

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