The analysis aims to describe processes of demographic and epidemiological change, as well as health status self-assessment in selected Central and Eastern Europe countries (CEECs), including both the new member states and the candidate countries. The analysis is presented in the context of the use of medical services and the structure of services used. Special attention is given to those demographic and epidemiological changes that have direct impact on the frequency of medical services used and, as such, determine increases in health care costs. The ageing process and health status improvement are the main hypothethical determinants of health care costs and are therefore presented in more detail. Additionally, changes in health behaviour – mainly in the use of medical services – are discussed in the context of institutional changes in the health care sector.