Which statement about hyperthyroidism is true according to the listed analyte changes?

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Multiple Choice

Which statement about hyperthyroidism is true according to the listed analyte changes?

Explanation:
When thyroid hormone levels rise, the pituitary reduces TSH secretion through negative feedback. In classic primary hyperthyroidism, the thyroid overproduces hormones, so FT4 is increased while TSH is decreased. This pattern—elevated FT4 with suppressed TSH—best fits hyperthyroidism. If FT4 were low with high TSH, that would indicate hypothyroidism; if FT4 were high with high TSH, that would suggest a TSH-secreting pituitary issue rather than primary hyperthyroidism; both low would point to central hypothyroidism or a non-thyroidal illness effect.

When thyroid hormone levels rise, the pituitary reduces TSH secretion through negative feedback. In classic primary hyperthyroidism, the thyroid overproduces hormones, so FT4 is increased while TSH is decreased. This pattern—elevated FT4 with suppressed TSH—best fits hyperthyroidism. If FT4 were low with high TSH, that would indicate hypothyroidism; if FT4 were high with high TSH, that would suggest a TSH-secreting pituitary issue rather than primary hyperthyroidism; both low would point to central hypothyroidism or a non-thyroidal illness effect.

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