The relationship between income and health is not always clearly defined. For example, is it income alone that explains differences in health between those with higher income and those with lower incomes? Or is it the differences between income levels juxtaposed with other factors, such as education?

Invariably, socioeconomic status, social class, and social position influence health outcomes across racial and ethnic groups, gender, and age. The impact of income on disparities in morbidity and mortality can be observed as you move along the income hierarchy.