Major emergencies like food shortages and prolonged nutritional issues can impair nutritional status and lead to excessive mortality. Common deficiency diseases in emergencies include protein energy malnutrition and micronutrient deficiencies. The type of disaster, duration, size of affected area, and pre-disaster nutritional status determine food and nutrition problems. Vulnerable groups include those with physiological or geographical vulnerabilities as well as internally displaced people and refugees. Management of nutrition in emergencies focuses on meeting energy, protein, and micronutrient requirements through food aid and treatment of existing malnutrition cases.