http://jech.bmjjournals.com/cgi/content/abstract/54/12/923

Inequalities in health are undesirable to the extent that they are unfair, or unjust. Distinguishing between health inequalities and health inequities can be contentious. Our view is that inequalities become "unfair" when poor health is itself the consequence of an unjust distribution of the underlying social determinants of health. Conditions that lead to marked health disparities are detrimental to all members of society. Some types of health inequalities have obvious spillover effects on the rest of society, for example, the spread of infectious diseases, the consequences of alcohol and drug misuse, or the occurrence of violence and crime. Disparities in health are avoidable to the extent that they stem from identifiable policy options exercised by governments, such as tax policy, regulation of business and labor, welfare benefits and health care funding.