Weird Thyroid Function Tests (TFTs)
Trevor E Angell, MD
Keck Medicine of USC
The assessment of thyroid function is among the most common evaluations performed by an endocrinologist or primary care provider. Despite the frequency of thyroid evaluation, knowledge of thyroid physiology, and accuracy of testing, there are still numerous scenarios in which thyroid function tests may be confusing or difficult to interpret. A strong understanding of thyroid testing is necessary to provide optimal patient care. Doing so requires an understanding of the breath of potential thyroid conditions, recognizing limitations and pitfalls that exist in thyroid function testing, and a systematic approach to “weird” TFT patterns when they arise. To address the most relevant scenarios representing challenging thyroid test interpretations, we will review important principles of thyroid hormone physiology, describe the most relevant thyroid function disorders to have in the differential diagnosis while interpreting TFTs, and explore case examples to broaden the learners’ knowledge and ability.