How do epidemics spread? The short, standard answer is through contagion. For most infectious disease epidemics, we are well aware that this happens through the transfer of microbes between people or between animals and humans. The COVID-19 pandemic has made this clear all around the globe, and many people have become increasingly aware of epidemic dynamics and concepts. Yet not all epidemics can be attributed to infection. A large part of the global burden of disease is due to so-called noncommunicable diseases. 1 How do these and other non-infectious conditions spread? Can they even be termed epidemic and contagious? This book offers ways to think about and expand our understanding of contagion beyond typical notions of infectious pandemics, beyond viral emergencies, to include the larger field of biosocial epidemics. Fundamentally we challenge the notion of noncommunicability (Seeberg and Meinert 2015), as it seems to render the epidemic spread of other forms of disease impossible. Some researchers have even proposed that we stop using the category of noncommunicable disease (Adjaye-Gbewonyo and Vaughan 2019; Blundell and Hine 2018) because many of these diseases are in fact communicable. In this book, we propose varied and detailed answers to questions about the epidemic and contagious potentials of specific infections and non-infectious conditions. We explore how inseparable social and biological processes configure co-existing influences which create epidemics, and we stress the role of social inequality in these processes. We use the term biosocial -in