The Handbook of presents a timely and up-to-date overview of the broad and substantial research efforts that have been invested in recent decades to understand how health communication affects health knowledge, perceptions, and discussion as well as health behaviours and, ultimately, health outcomes. The handbook is structured to reflect and address essential parts of the communication process: sender, content, medium, and recipient. In addition to providing a historical and contemporary overview, the handbook also acknowledges the novel challenges that emergent media present for health communication, such as infodemics and misinformation.