Thyroid Hormones

Publication Date: August 31, 2023

Key Points

Key Points

  • The “quality” of thyroid testing is defined by its ability to discriminate among hyperthyroid, hypothyroid and euthyroid, including subclinical conditions.
  • Over the past 65 years, a progressive improvement in methods to quantitate clinically relevant thyrotropin (TSH), thyroxine (T4), and triiodothyronine (T3) concentrations has led to this state-of-the-art status report on current recommendations.
  • Because of the log-linear relationship of TSH to free T4 (fT4), deviations of TSH concentration from population-specific reference intervals represent the preferred initial test for evaluation of thyroid function.

Interpreting Thyroid Tests

Interpreting Thyroid...

...able 1. Key Clinical Points for Interpreting Thyr...

Nowadays, most thyroid tests are made on multi...


Clinical Thyrotropin Measurements

...al Thyrotropin Measurements...

...able 2. Points to Consider for Clinical Thyr...


...matic Presentation of Dynamic Changes of Se...


...3. Common Physiological and Pharmaco...


...le 4. Rarer Causes of Perturbation of the Hypotha...


...5. Clinical Utility of Triiodothyronin...


...auses of Artifactual Results in Thyroid Horm...


...2. Status of Comparability of Results...