Which hormone is measured to assess thyroid function?

The hormone measured to assess thyroid function is Free T4. This hormone, also known as free thyroxine, plays a critical role in the regulation of metabolism and is produced by the thyroid gland. When evaluating thyroid health, measuring Free T4 gives insight into how well the thyroid is functioning and how much active hormone is available in the bloodstream to exert its effects on various physiological processes.

Assessing Free T4 levels helps in diagnosing conditions such as hypothyroidism (where levels are low) or hyperthyroidism (where levels are elevated). It is commonly measured alongside TSH (Thyroid Stimulating Hormone) to provide a more comprehensive picture of thyroid health. Other hormones mentioned, such as DHEA sulfate, FSH, and estradiol, serve different functions related to adrenal, reproductive, and overall endocrine system health but are not directly involved in measuring thyroid function.