Answer: Serum thyroid-stimulating hormone test would confirm secondary hypothyroidism.
Explanation:
The serum thyroid stimulating hormone (TSH) test involves the intravenous administration of a small amount of Thyroid Releasing Hormone (TRH) and the measurement of TSH levels at some points following the administration.
The first step involves collecting the blood sample of the patient and measuring the baseline TSH prior to the intravenous administration of TRH. Blood sample is drawn again 30 minutes after TRH administration, and TSH level is measured and compared to the baseline measurement.
If there is slight or no increase in serum TSH level following TRH administration, it is secondary hypothyroidism because the cause of the hypothyroidism is in the anterior pituitary gland. This means that the pituitary gland is not secreting TSH because it is diseased.
