Endocrine Review of Systems Questions Related

Review Endocrine Review of Systems Questions related questions and content

Blood levels of which of the following substances is decreased in Graves disease?

  • A. Triiodothyronine (T3)
  • B. Thyroxine (T4)
  • C. Diiodotyrosine (DIT)
  • D. Thyroid-stimulating hormone (TSH)
Correct Answer: D

Rationale: In Graves disease, there is an overproduction of thyroid hormones due to autoimmune stimulation. Thyroid-stimulating hormone (TSH) is decreased because the excessive thyroid hormones suppress its production through negative feedback. A and B are incorrect because both T3 and T4 levels are elevated in Graves disease. C is incorrect as DIT is a precursor to thyroid hormones and its levels may not necessarily be decreased in Graves disease.