City planning as preventive medicine.

The health and well-being of rapidly growing urban populations is a global health issue. Cities in the global north and south are faced with rising health inequities - or avoidable differences in health determinants and outcomes based on place, social status and ethnicity. This commentary suggests that focusing only on treatment interventions in cities is likely to fail because populations will be forced to go back into the urban living and working conditions that likely made them sick in the first place. City planning as preventive medicine includes taking a relational and systems approach to urban health, requiring health assessments for all urban policy making, promoting neighborhood health centers as engines of community economic development and gathering place-based health indicator data to track progress and adapt interventions over time as conditions change.