The best marker to diagnose thyroid related disorder is
Answer is C (TSH) : The enhanced sensitivity and specificity of TSH assays have greatly improved laboratory assessment of thyroid function - Harrison With rare exceptions a normal TSH level excludes a primary abnormality of thyroid function.- Harrison Approach to thyroid testing: Because TSH change dramatically in response to alteration of free T4 and T3, a logical approach to thyroid testing is to determine first whether TSH is suppressed, normal or elevated - Harrison
T3
T4
TSH
Thyroglobulin