A syndemic is the aggregation of two or more diseases in a population in which there is some level of positive biological interaction that exacerbates the negative health effects of any or all of the diseases. The term was developed and introduced by Merrill Singer in several articles in the mid-1990s and has since received growing attention and use among epidemiologists and medical anthropologists concerned with community health and the effects of social conditions on health, culminating in a recent textbook. Syndemics tend to develop under conditions of health disparity, caused by poverty, stress, or structural violence, and contribute to a significant burden of disease in affected populations. The term syndemic is further reserved to label the consequential interactions between concurrent or sequential diseases in a population and in relation to the social conditions that cluster the diseases within the population.