When one approaches diseases from a historical perspective, it is striking that most diseases display a spectacular pattern of rise and fall. This article discusses an 'ecological-evolutionary theory' of the origins of disease, which explains the emergence of ever-new diseases from the fact that humans, in their tireless pursuit of better living conditions, have engaged in activities that exposed them to new health risks, at a pace that evolution cannot keep up with. This is illustrated by examples in the field of infectious diseases, ischemic heart disease and cancer. The rise of COVID-19 can be understood along the same lines. The fundamental role of behaviour and environment in the development of disease implies that public health measures are generally the best approach to tackle disease. Conflict of interest and financial support: none declared.