This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
The Lab ivestigationofpatient shows|T3,|T4, &|TSH.It cannotbe- 
Select and explain. 
A. Primaryhypothyrodism, B. Pan-hypopmuarlsm, C. liverdisease, D. None of the above
A: Primaryhypothyrodism
Answer: A: Primaryhypothyrodism 
Explanation: 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