In case of hypothyroidism which investigation is most informative and most commonly used:: (A) Serum TSH level, (B) Serum T3 and T4 level, (C) Serum calcitonin assay, (D) Serum TRH assay
Answer is A. TSH* Most informative among thyroid function test parameters because of ultra-sensitivity* Can detect subclinical hypothyroidism & subclinical hypehyroidism* Hypothyroidism - TSH |* Hypehyroidism - TSH |