This book is a journey around the vast subject of the thyroid, designed to share information about its functioning and the pathologies that can affect it. It is intended to provide accessible and simplified language, distancing itself from technicalities of the medical profession. It represents an itinerary that invites step-by-step learning and taking care of one's own health through prevention and the adoption of healthy lifestyle habits. Reading it helps improve visual memory and facilitates the acquisition of concepts, shortening the distances for both the reader and the specialist. The medical-scientific information maintained in this book maintains its authoritative nature while promoting sharing. This book is for everyone: young, adults, and the elderly. It is for you, for your well-being and the well-being of your loved ones.