<prompt> The Lab ivestigationofpatient showsT3,T4, TSH.It cannotbe-PrimaryhypothyrodismPan-hypopmuarlsmliverdiseaseNone of the above  <response>: Ans is option 1 - primary hypothyroidism The single most useful measurement for assessment of hypothyroidism is serum TSH. It is increased in primary hypothyroidism. To compensate the reduced T3 and T4 there is a hypersecretion of TSH. Ref Harrison 19 2289 