Which of the following is the most useful investigation for thyroid function: September 2011: (A) T3, (B) T4, (C) TSH, (D) TRH
Answer is C. Ans. C: TSH TSH is usually regarded as the most useful investigation of thyroid function Thyroid pathology: Primary hypehyroidism: - Decreased TSH - Raised T4 Secondary hypehyroidism: Raised TSH Hypothyroidism: Raised TSH