#408 ‒ AMA #89: Thyroid health: interpreting symptoms, diagnosing and treating dysfunction, and navigating the gray zone

About this episode

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter's Weekly Newsletter In this "Ask Me Anything" (AMA) episode, Peter takes a deep dive into thyroid health and explains why diagnosing and managing thyroid dysfunction is unusually complex. He begins with the basic biology of the thyroid gland and three commonly measured hormones—free T4, free T3, and TSH. He explains how T4 is converted to the active hormone T3 and the important functions T3 performs throughout the body. He also explains what reverse T3 is and when it may be useful to measure it. Peter then breaks down thyroid blood tests and their limitations and provides a practical framework for evaluating suspected thyroid dysfunction. He explains why symptoms alone are insufficient for diagnosis and reviews the criteria for diagnosing hypothyroidism, along with conditions that can mimic it. He also explores how hypothyroidism can be both underdiagnosed and overtreated and how to navigate subclinical hypothyroidism. Peter discusses treatment with T4 and T3, including why some patients continue to experience symptoms despite standard T4 replacement. He also expl