Humanitarian crises exacerbate nutritional risks and often lead to an increase in acute malnutrition. Emergencies include both manmade (conflict) and natural disasters (floods, drought, cyclones, typhoons, earthquakes, volcanic eruptions, etc.). Complex emergencies are combinations of both manmade and natural disasters, often of a protracted nature. Millions of people are affected by humanitarian crises every year. The increasing frequency and scale of emergencies requires nutrition to be addressed in all phases of a response. Crisis situations, whether acute or protracted, impact on a range of factors that can increase the risk of undernutrition, morbidity, and mortality. They may involve: the large-scale destruction of property and infrastructure; the erosion of livelihood strategies and purchasing power; a breakdown of and reduced access to essential services, including health services, water supply, and sanitation; and the displacement of large numbers of people. Emergencies can also disrupt social systems and the quality of care/feeding practices. Household access to food may be negatively affected and people may find themselves in overcrowded settlements with their families divided. As a result, at the individual level, there is often an increased risk of deteriorating health and nutritional status, resulting in a greater likelihood of death.