Floods may be caused by natural processes that are either fluvial or coastal in origin. Generalized food shortages, severe enough to cause nutritional problems, usually do not occur after disasters but may arise among low-income nations. Displacement is a key risk factor for morbidity and mortality among disaster-affected populations. Flooding may directly damage healthcare facilities or it may hinder public access to these facilities by closing transportation routes. The number of deaths associated with flooding is closely related to the life-threatening characteristics of the flood and by the behavior of the victims. Causes of flood-related morbidity reported in high-income nations during the first 6 weeks after the disaster are frequently equally divided between injuries and illnesses. Sustainable flood risk management seeks to reduce risk at all stages of the disaster cycle giving preference to more cost-effective disaster risk reduction activities such as prevention, preparedness, and mitigation.