Malnutrition refers to both undernutrition and overnutrition. Undernutrition is caused by a lack of nutrient intake and can increase risk of infection and chronic disease. It includes protein-calorie malnutrition like kwashiorkor and marasmus in children. Micronutrient deficiencies like vitamin A, iron, and iodine deficiencies can also cause health problems. Nutritional status can be assessed directly using anthropometric, clinical, dietary, and biochemical methods or indirectly using community indices.