Background

3. Thyroid tests

The two most commonly used laboratory evaluations to test thyroid function are free T4T4 - thyroxine thyroid hormone and thyroid stimulating hormone (TSHTSH - Thyroid stimulating hormone; also known as thyrotropin. The hormone that causes the thyroid to make and release thyroid hormone). Because over 99% of released thyroid hormone is attached to proteins in the blood, it is believed that measuring the amount not attached to proteins (i.e., free thyroid hormone) is a more accurate measurement of thyroid hormone levels. Measuring the total hormone level is generally less reliable.

Common thyroid function tests

AssayHigh levelLow level
TSHHypothyroidismHyperthyroidism
Free T4HyperthyroidismHypothyroidism
Free T3 HyperthyroidismHypothyroidism
TgMay indicate cancer recurrence after total thyroidectomyAdequate treatment after removal or ablation of thyroid
TSH-R AbGraves' disease
Anti TG AbHashimoto's thyroiditis
Anti TPO AbHashimoto's thyroiditis
CalcitoninMedullary thyroid cancer

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THE PAUL LOGERFO EDUCATION RESEARCH FUND
PAUL LOGERFO EDUCATION RESEARCH FUND Supporting education and research in the field of Endocrine Surgery as a tribute to former President, Dr. Paul LoGerfo.
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