Health equity arises from access to the social determinants of health, specifically from wealth, power and prestige. Individuals who have consistently been deprived of these three determinants are significantly disadvantaged from health inequities, and face worse health outcomes than those who are able to access certain resources. It is not equity to simply provide every individual with the same resources; that would be equality. In order to achieve health equity, resources must be allocated based on an individual need-based principle.

According to the World Health Organization, "Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". The quality of health and how health is distributed among economic and social status in a society can provide insight into the level of development within that society. Health is a basic human right and human need, and all human rights are interconnected. Thus, health must be discussed along with all other basic human rights.

Health equity is defined as differences in health that are unavoidable, unfair, and unjust, and cannot be explained by natural causes, such as biology, or differences in choice. It is closely associated with the social justice movement, with good health considered a fundamental human right. Thus, if one population dies younger than another because of genetic differences, a non-remediable/controllable factor, we tend to say that there is a health inequality. On the other hand, if a population has a lower life expectancy due to lack of access to medications, the situation would be classified as a health inequity. These inequities may include differences in the "presence of disease, health outcomes, or access to health care"^: 3 between populations with a different race, ethnicity, gender, sexual orientation, disability, or socioeconomic status. Although it is important to recognize the difference in health equity and equality, having equality in health is essential to begin achieving health equity. The importance of equitable access to healthcare has been cited as crucial to achieving many of the Millennium Development Goals.