The Basics
What is the number of TSH tests done yearly in US?
Assays of this free hormone are most accurate
What is free T4?
This is a marker of thyroid autoimmune problems
What is thyroglobulin antibody (Tg-Ab)?
A marker of differentiated (papillary and follicular) thyroid cancer
What is thyroglobulin?
Low TSH and Low T4, pt does not take Biotin
What test results show secondary (from the pituitary) hypothyroidism?
What Is the hypothalamus?
This common dietary supplement interferes with tests for TSH and Free T4
What is biotin?
Always elevated in Hashimoto’s thyroiditis
What is Thyroid peroxidase antibodies (TPO-Ab)?
A marker of medullary thyroid cancer
What is Calcitonin?
Low TSH and low T4, pt takes Biotin and did not hold it prior to test
What sugests euthyroid state with likely assay interference?
What is T3 (triiodothyronine)?
This normal physiological state makes thyroid function test interpretation challenging What is pregnancy?
What is pregnancy?
A stimulating thyroid antibody found only in Graves disease
What is TSH receptor antibody (TRAb)?
A marker of medullary thyroid cancer that is less prone to assay interference
What is procalcitonin?
Low TSH and normal T4
What is subclinical hyperthyroidism?
Deiodinases
What converts T4 to T3
It is unclear if these changes in thyroid levels are harmful or helpful
What are thyroid levels in pregnancy?
The most common cause of hypothyroidism when idodine is prevalent
What is Hashimotos thyroditis
This type of thyroid nodule has a low chance of malignancy
What is a hyperfunctioning thyroid nodule?
T4 is normal, but TSH is still elevated, only slightly less so than on initial hypothyroidism diagnosis 6 weeks ago, despite starting Levothyroxine
What happens when a patient takes Levothyroxine for a day or two only, right before the blood draw?
Provides negative feedback to Hypothalamus and Anterior pituitary
What are free thyroid hormones?
Measure thyroglobulin and thyroglobulin antibody
What is the best way to follow the progress of differentiated thyroid cancers (pappilary and follicular)?
This condition causes both hypo and hyperthyroidism
What is Hashimotos?
Patients with a thyroid nodule who are euthyroid or hyopothyroid need this to rule out malignancy
What is a fine needle biopsy (+/- genetic testing)?
Low TSH, low T4 and high T3
What will thyroid tests show when a patient takes Cytomel (Liothyronine) to augment antidepressants?