WHO’s Member States face a broad range of emergencies resulting from various hazards and differing in scale, complexity and international consequences. These emergencies can have extensive political, economic, social and public health impacts, with potential long-term consequences sometimes persisting for years after the emergency. They may be caused by natural disasters, conflict, disease outbreaks, food contamination, or chemical or radio-nuclear spills, among other hazards. They can undermine decades of social development and hard-earned health gains, damage hospitals and other health infrastructure, weaken health systems and slow progress towards the Millennium Development Goals (MDGs). Preparing for and responding effectively to such emergencies are among the most pressing challenges facing the international community.