TSH w/ Reflex to Free T4

A TSH with reflex to free T4 test, also known as a thyroid stimulating hormone test with reflex to free T4, is a two-step blood test used to evaluate thyroid function. It first measures TSH levels, and if those are abnormal, it automatically proceeds to measure free T4 levels without requiring a separate blood draw. This approach helps diagnose thyroid disorders like hypothyroidism and hyperthyroidism more efficiently.