Generally the most common cause worldwide has been dehydration from diarrhea, a preventable disease; however, a variety of programs combating this problem have decreased the rate of children dying from dehydration. Many factors contribute to infant mortality such as the mother's level of education, environmental conditions, and political and medical infrastructure. Improving sanitation, access to clean drinking water, immunization against infectious diseases, and other public health measures could help reduce high rates of infant mortality.