What health risks arise in shrinking cities? A systematic review

Shrinking cities are urban areas experiencing sustained population loss alongside broader socioeconomic, spatial, and institutional restructuring. As this process becomes more widespread, it is increasingly recognized as an important structural determinant of population health. However, the pathways linking urban shrinkage and health remain fragmented across the literature. This systematic review synthesizes 56 peer-reviewed studies published between 2006 and 2026 to examine how urban shrinkage has been conceptualized and how it affects health across five domains: physical health, mental health, healthcare access and systems, air quality and pollution, and urban heat stress. The findings show that urban shrinkage has been defined and measured in diverse ways, most commonly through long-term population decline, but also through indicators of vacancy, ageing, and economic contraction. Across the reviewed studies, health effects emerged through multiple interacting processes rather than a single pathway. These effects were often nonlinear and strongly context-dependent, particularly in relation to environmental outcomes. Based on these findings, this review proposes three main pathways through which urban shrinkage affects health: structural weakening, psychosocial distress, and environmental deterioration. Overall, the review suggests that urban shrinkage should be understood not simply as a demographic trend, but as a broader process of restructuring with cumulative implications for health. Policy responses should therefore move beyond simple service contraction and instead prioritize adaptive health system design, the managed reuse of vacant land, and context-sensitive environmental interventions to support healthier and more resilient shrinking cities.