Many different forms of migration exist and human mobility shapes global health, impacting on domestic and foreign policies of sending, transition and receiving countries. The health of migrants is influenced by these different policies and legal frameworks but also by the practices surrounding migration. Yet, the act of migration alone does not cause any disease. Rather, the socioeconomic, political, cultural and environmental conditions connected to the act of migration can impact on health and the vulnerability to disease. National health systems are often put under pressure to respond to large-scale movements and diplomacy comes into play to find cross-border, collective solutions. Health can serve as an entry point for these diplomatic actions and new governance mechanisms need to be negotiated to respond appropriately to migration crises.