• Many countries are experiencing the "double burden" of high rates of Group 1 diseases and Group 2 diseases at the same time • Group 1 - communicable/infectious, perinatal, maternal, and nutritional • Group 2 - non-communicable • Sometimes these different groups of diseases are occurring in different populations within the same country • The affluent are more likely to have a high burden of non-communicable diseases • The poor are more likely to have a high burden of diseases of extreme poverty • Having high rates of both types can be taxing on the health system