Socio-demographic characteristics such as sex, age, participation in risky behaviour (i.e., drinking alcohol, smoking), as well as living and working conditions are among the most important determinants of an individual’s health. A healthy migrant effect is expected to be found in countries where the bulk of migration is composed of recent migrants, younger on average than the native-born population. This positive effect is expected to diminish as the duration of residence grows longer. The origin country of migrants and the conditions of the migration may nuance the positive impact of the immigration self-selection on health outcomes. Some migrant groups, such as refugees, are particularly vulnerable and may be more likely to suffer from specific diseases or mental disorders. More generally, the migratory experience can lead to stress which may affect migrants’ health outcomes in different ways down the line, depending on socio-economic and health conditions in the country of origin and on the extent to which they settle in the receiving country. Finally, a positive correlation generally exists between both educational attainment and income level, on the one hand, and health status, on the other. This chapter analyses several aspects of self-reported health status for both the native-born and immigrant populations (Indicator) as well as unmet medical needs (Indicator). For a discussion on these indicators, refer to the section Measurement at the end of this chapter.