Evidence on the health–poverty cycle and its mechanisms in low- and middle-income countries

In low- and middle-income countries, poor health remains a major driver of household impoverishment despite extensive health sector reforms. Beyond economic consequences, this relationship raises ethical concerns related to equity, justice, and collective responsibility for protection against health risks. This structured narrative review, informed by a systematic search strategy used to identify and transparently select relevant studies, examines how poor health contributes to economic vulnerability, identifies the mechanisms through which this process operates, and discusses its normative and ethical implications for health systems and public policy. There are three interrelated mechanisms that are used as an analytical framework to structure the review namely: unplanned and catastrophic health expenditures, illness-related income losses, and indirect effects on human capital. The review draws on empirical, conceptual, and policy literature published between 2001 and 2025, selected according to predefined inclusion criteria, with PRISMA 2020 used as a reporting guide to improve transparency in the presentation of the search and selection process. Therefore, studies are analyzed according to the mechanisms linking ill health to impoverishment and their relevance to equity and social justice. The Moroccan case is included as an illustrative example based on secondary sources and does not constitute a primary empirical analysis. The findings highlight that these mechanisms interact cumulatively, forming a persistent health–poverty vicious circle in which poor health increases economic vulnerability, while socio-economic disadvantage heightens exposure to health risks. Insufficient financial protection and unequal risk distribution reflect broader inequalities in social protection and raise concerns regarding justice and the dignity of individuals and households. However, breaking this cycle requires integrated strategies that combine financial protection, income security, and human capital preservation, guided by ethical principles of equity and justice.