4 Health Disparities and Health Equity

Core concepts

Health is shaped by biology and personal choices, as well as by the conditions in which people live and the way society distributes resources and opportunities. These influences help explain why preventable differences in health occur and where action to reduce them may be needed.

Health disparities are patterned differences in health outcomes or opportunities for good health among population groups. Health inequities are disparities that are unfair, avoidable, and connected to remediable social conditions. Health equity means everyone has a fair opportunity to attain their full health potential; it does not mean everyone has identical health outcomes or needs.

These concepts focus attention on patterns across groups rather than treating each person’s health as an isolated event. A disparity signals a need to investigate causes, but the label by itself does not explain them.

Social determinants of health

Social determinants of health (SDOH) are conditions in the environments where people are born, grow, learn, work, live, play, worship, and age, together with the broader forces that shape those conditions. They are grouped into five connected domains:

• Economic stability: income, employment, food security, and financial resources.

• Education access and quality: early learning, school quality, literacy, and educational opportunity.

• Health care access and quality: availability, affordability, accessibility, and quality of services.

• Neighborhood and built environment: housing, transportation, safety, green space, and air and water quality.

• Social and community context: social support, civic participation, discrimination, and experiences of inclusion or exclusion.

The domains interact. For example, a low-wage job may offer little schedule flexibility or paid leave, making it difficult for a worker to attend medical appointments. An unreliable bus route may make the trip longer, delaying care even when a clinic is nearby.

Patterns and pathways

Disparities may appear in disease risk, illness, disability, life expectancy, exposure to hazards, and access to timely, high-quality care. They can occur between neighborhoods, regions, or social groups, and may vary across conditions and over time.

Broad population categories do not describe every person within them. Income, location, age, disability, and other circumstances can shape health within any population group, and people may experience multiple, overlapping influences.

Tracing pathways

A useful way to understand a disparity is to trace how social conditions may connect to health. For example, housing policies and unequal investment can contribute to poorly maintained housing near traffic or industrial pollution. Greater exposure to indoor and outdoor pollutants can worsen respiratory health, while limited access to primary care or safe places to exercise may add further risks.

These conditions can combine, but the example does not mean that everyone in a neighborhood has the same experience. Health is also influenced across the life course: early-life conditions can affect development and later opportunities, while accumulated exposures and resources can influence health in adulthood and older age. Research frameworks examine influences at multiple levels, from individual and interpersonal factors to community and societal conditions.

Structural influences

Structural determinants are political, legal, economic, and institutional arrangements that shape the distribution of power, resources, and opportunity. Laws, policies, institutional practices, and social norms influence access to education, stable work, safe housing, health services, and environmental protection.

Discrimination and structural racism can operate through these systems and contribute to unequal conditions. Disparities should not be interpreted as evidence of inherent differences in people’s worth or ability.

Many root causes lie outside health-care settings, so medical services alone cannot eliminate all disparities. Health care remains essential, but its benefits depend in part on whether people can reach services, afford them, communicate with providers, and receive respectful, effective care. Health outcomes are influenced both by health systems and by policies in housing, education, employment, transportation, and environmental protection.

Approaches to advancing health equity

Advancing equity requires coordinated work at several levels:

1. Measure disparities carefully. Compare relevant health outcomes and access measures across population groups and places. Use consistent definitions, examine data quality, and do not treat broad categories as interchangeable with individuals.

2. Investigate causes. Look beyond gaps to the policies, institutions, exposures, and barriers that may produce a pattern. Combine population data with community knowledge and lived experience.

3. Work with affected communities. Engage residents and community organizations in setting priorities, choosing interventions, and interpreting results. Participation can help responses fit local needs and build on community strengths.

4. Combine clinical and upstream action. Improve the availability, affordability, accessibility, and quality of care while also addressing conditions such as unsafe housing, food insecurity, pollution, and transportation barriers. Multiple sectors may need to work together to address structural drivers and their effects.

5. Evaluate and adjust. Track health outcomes and the conditions an intervention is intended to change. Assess who benefits, whether gaps narrow, and whether unintended harms arise; use findings to improve or redirect the approach.

For example, a community seeking to reduce asthma-related emergencies might pair accessible, high-quality clinical care with home-based asthma-management support and efforts to reduce housing-related triggers. Tracking emergency visits alongside housing conditions can help assess whether both immediate needs and contributing conditions are being addressed.