Most health disparities are preventable. The CDC defines health disparities as preventable differences in the burden of disease, injury, violence, or opportunities to be healthy, directly tied to the unequal distribution of social, political, economic, and environmental resources. The key word in that definition is “preventable”: these are not inevitable biological differences between groups but gaps created by systems and conditions that can be changed.
That said, “preventable” does not mean “simple to fix.” The forces driving health disparities are deeply embedded in housing policy, income inequality, environmental exposure, and access to care. Understanding where these gaps come from is the first step toward seeing why experts consider them solvable.
Medical Care Accounts for Less Than You Think
One of the most important numbers in public health is this: only about 20 percent of health outcomes are linked to medical care. The remaining 80 percent stem from socioeconomic, environmental, and behavioral factors, sometimes called social drivers of health. That includes where you live, how much money you make, what you eat, how much pollution you breathe, and whether your neighborhood is safe enough to walk in.
This ratio explains why building more hospitals or expanding clinic hours, while helpful, can’t close health gaps on its own. If two people have the same disease but one lives in a neighborhood with clean air, safe sidewalks, affordable grocery stores, and stable housing while the other doesn’t, their outcomes will differ regardless of whether both see the same doctor. Preventing disparities means addressing the conditions people live in, not just the conditions they’re diagnosed with.
How Historical Policy Still Shapes Health Today
Some of the starkest health disparities trace back to decisions made nearly a century ago. Redlining, a federal policy from the 1930s that graded neighborhoods by perceived investment risk (which was largely based on racial composition), was officially abolished in 1968. But its effects are measurable today. A study examining California neighborhoods found that formerly redlined areas have dramatically worse environmental quality than neighborhoods that received favorable ratings. In redlined neighborhoods, 77 percent had pollution burdens above their city’s average, compared to just 18 percent in the highest-rated neighborhoods. The pattern held across every hazard measured: 72 percent of redlined neighborhoods had elevated temperatures versus 20 percent of top-rated ones, 86 percent had less vegetation versus 12 percent, and 72 percent had more noise versus 18 percent.
These aren’t abstract statistics. Higher pollution means more asthma and cardiovascular disease. Elevated temperatures mean more heat-related illness and death. Less green space means fewer places for physical activity and higher stress. Communities of color are disproportionately exposed to these hazards because of where racist zoning practices concentrated them decades ago. The policy is gone, but the geography it created persists, and so do the health consequences.
Maternal Mortality: A Case Study in Preventability
Pregnancy-related deaths offer one of the clearest illustrations of preventable disparity. Research shows that nearly half of severe complications and maternal deaths could have been avoided with better care. But the risk is not evenly distributed: 46 percent of Black maternal deaths were classified as potentially preventable, compared to 33 percent of white maternal deaths. That 13-point gap represents lives that could have been saved.
The preventability factors are not mysterious. They include delayed or inappropriate diagnosis, communication failures between providers, and hospital policies that weren’t followed. These are system problems, not biological ones. When a Black woman’s pain is taken less seriously, when her symptoms are dismissed, or when her hospital lacks standardized protocols for obstetric emergencies, the resulting harm is a product of how care is delivered, not an inevitable outcome of pregnancy.
Screening Gaps Show Where Access Falls Short
Cancer screening is one of the most effective tools for catching disease early, when treatment works best. But screening rates vary sharply depending on whether someone has insurance, a regular doctor, or enough income to prioritize preventive care.
For colorectal cancer screening, the overall rate among women aged 50 to 75 was about 63 percent. But for uninsured women, it dropped to 45 percent. Women with no regular source of health care screened at 46 percent. Among men, the pattern was similar: uninsured men screened at 49 percent, and those without a regular doctor at just 42 percent. Mammography showed comparable gaps. While the overall rate for women aged 50 to 74 was about 72 percent, uninsured women screened at only 54 percent, and those without a usual source of care at 53 percent.
These gaps mean that people without insurance or a regular doctor are more likely to have cancer detected at a later stage, when it’s harder and more expensive to treat. The disparity isn’t caused by people choosing not to get screened. It’s caused by not having a doctor to recommend it, not being able to afford it, or not having insurance to cover it. Each of those barriers is, in principle, fixable.
Chronic Disease Complications Follow the Same Pattern
Diabetes is the seventh leading cause of death in the United States, responsible for over 95,000 deaths in 2023. One of its most serious complications is chronic kidney disease, and the risk is not equally distributed. Among adults with diagnosed diabetes, 24.7 percent of non-Hispanic Black adults had moderate to severe kidney disease, compared to 18.4 percent of non-Hispanic white adults. Diabetes is also the leading cause of new blindness among adults aged 18 to 64.
The gap in kidney disease rates reflects differences in blood sugar control, blood pressure management, access to specialty care, and the cumulative stress of living in under-resourced communities. These are all areas where targeted intervention can make a difference. Better access to nutritious food, consistent primary care, and affordable medications can slow or prevent the progression from diabetes to kidney failure.
What Happens When Policy Intervenes
If disparities are created by systems, changing those systems should help. The evidence from Medicaid expansion offers a partial test of that idea. When states expanded Medicaid eligibility, low-income adults saw significant gains in insurance coverage, access to a personal doctor, and the ability to afford care. For non-Hispanic Black adults, the gap in having a personal doctor narrowed compared to white adults in expansion states.
But insurance expansion alone doesn’t erase every disparity. Hispanic adults saw fewer benefits from Medicaid expansion, and some gaps actually widened for that group. This underscores a critical point: no single policy addresses all the drivers of health inequality. Language barriers, immigration status, geographic isolation, and cultural factors all shape whether a person can use the coverage they technically have. Closing disparities requires layered interventions that address multiple barriers at once.
Why “Preventable” Doesn’t Mean “Easy”
The U.S. government’s Healthy People 2030 framework sets an explicit national goal to “eliminate health disparities, achieve improved health for all people, and attain health literacy to improve the health and well-being of all.” The fact that this goal exists at the federal level reflects a broad consensus: these gaps are not natural or inevitable, and reducing them is a matter of policy and resource allocation.
Still, calling something preventable is different from preventing it. The 80 percent of health outcomes driven by social and environmental factors involves entrenched systems of housing, employment, education, and environmental regulation. Changing those systems requires sustained political will, funding, and coordination across sectors that don’t traditionally work together. A hospital can’t fix a patient’s housing. A school can’t clean up a nearby Superfund site. But housing agencies, environmental regulators, school systems, and health care providers working toward the same goals can, over time, reshape the conditions that produce disparities in the first place.
The evidence is clear that health disparities are not biologically determined. They are produced by identifiable, modifiable conditions. Whether they’re actually prevented depends on whether the resources and commitment exist to change those conditions.