Race itself is not a biological risk factor for disease, but it is deeply connected to the social determinants of health. The conditions that shape health outcomes, including where you live, what environmental hazards you’re exposed to, how much stress your body carries, and how you’re treated in a clinical setting, are all patterned along racial lines in the United States. Race functions as a powerful predictor of health not because of genetics, but because of the social and structural systems organized around it.
Race as a Social Construct, Not a Biological One
The National Human Genome Research Institute defines race as a social construct used to group people, one that was historically built as a hierarchical system to distinguish and marginalize certain groups. Racial categories are not fixed. They shift over time, across borders, and depending on context. The key genetic fact is this: there is more genetic variation within self-identified racial groups than between them. Two people who both identify as Black may be more genetically different from each other than either is from a person who identifies as White.
This matters because it reframes the question. When Black Americans have higher rates of hypertension, diabetes, or maternal death, the explanation is not found in their DNA. It is found in the environments, policies, and systems they navigate. Race does not cause poor health. Racism does, by determining access to the resources and conditions that make good health possible.
How Structural Racism Shapes Health Conditions
Social determinants of health are the non-medical factors that influence health outcomes: housing stability, income, education, neighborhood safety, food access, environmental quality, and exposure to discrimination. The CDC has stated explicitly that these determinants are “driven by intersecting systematic influences such as economic policies and institutional racism that unequally affect different populations.” In other words, the institutions and policies that distribute resources in society do not distribute them equally across racial groups, and health suffers as a result.
Consider housing. In the 1930s, the federal government systematically graded neighborhoods across the country, marking predominantly Black, Hispanic, and immigrant communities as high-risk zones for lending. This practice, known as redlining, was officially outlawed decades ago, but its footprint persists. A study published in Environmental Science & Technology Letters found that historically redlined neighborhoods today have significantly higher exposure to environmental hazards. After controlling for socioeconomic status, a neighborhood that had been redlined was 1.3 times more likely to face elevated levels of multiple environmental threats simultaneously. The most common hazards were proximity to hazardous waste sites, wastewater discharge, high traffic volume, and diesel particulate matter. Other research has linked these same neighborhoods to higher rates of air pollution, flooding, and urban heat islands.
These are not abstract statistics. They translate directly into higher rates of asthma, cardiovascular disease, heat-related illness, and cancer in communities that were marked as undesirable nearly a century ago. The policies that created these conditions targeted people by race. The health consequences follow the same lines.
The Biological Cost of Chronic Stress
One of the most compelling explanations for racial health disparities is the weathering hypothesis, developed by researcher Arline Geronimus. Weathering describes the physiological wear and tear that accumulates from living under sustained social and economic adversity. It is not simply feeling stressed. It involves chronic activation of the body’s stress response systems, including the hormonal pathways that regulate inflammation, metabolism, and immune function.
Over time, this constant activation changes the body at a cellular level. Researchers have found that it alters gene expression through a process called methylation, where chemical tags attach to DNA and switch certain genes on or off. These changes can be measured using epigenetic aging indexes, which estimate how quickly a person’s biology is aging compared to their actual calendar age. Studies using these tools have found that Black Americans show signs of accelerated biological aging, meaning their cells and organs are wearing out faster than expected. This accelerated aging contributes to earlier onset of chronic disease and shorter life expectancy.
The stressors driving this process are not limited to dramatic events. They include the daily friction of navigating discrimination, financial insecurity, unsafe neighborhoods, and the psychological burden of being treated differently in stores, schools, workplaces, and hospitals. The body does not distinguish between a single traumatic event and a lifetime of smaller insults. It responds to all of them.
Maternal Mortality: A Clear Example
Perhaps no health statistic illustrates racial disparities as starkly as maternal mortality. In 2024, Black women in the United States died from pregnancy-related causes at a rate of 44.8 per 100,000 live births. For White women, the rate was 14.2. Black women are roughly three times more likely to die during or shortly after pregnancy.
This gap does not disappear when you account for income or education. Studies have consistently shown that Black women with college degrees still face higher maternal mortality than White women without them. The disparity reflects a combination of factors: higher baseline rates of chronic conditions like hypertension (itself a product of weathering), less access to quality prenatal care, and well-documented patterns of clinical dismissal. Black women report having their pain minimized and their concerns ignored by healthcare providers at higher rates than their White counterparts.
Bias Built Into Medical Tools
The healthcare system itself contains tools that can produce different outcomes depending on race. Pulse oximeters, the small devices clipped to your finger to measure blood oxygen levels, have been shown to be less accurate on darker skin. Research reviewed by the Agency for Healthcare Research and Quality found racial and ethnic discrepancies in pulse oximetry readings that can lead to delays in diagnosis or treatment. If your oxygen levels are dropping but the device reads them as normal, you may not receive supplemental oxygen or escalated care when you need it.
This is one example of a broader pattern. For years, clinical algorithms in kidney function testing, lung capacity assessment, and cardiac risk scoring included race-based correction factors that assumed biological differences between racial groups. Many of these adjustments had no solid genetic basis and, in practice, made it harder for Black patients to qualify for referrals, transplants, or aggressive treatment. Medical institutions have begun removing these race-based adjustments, but the process is ongoing and uneven.
What This Means in Practice
If you are trying to understand why health outcomes differ so dramatically by race in the United States, the answer is layered but consistent. Race determines, on average, the neighborhood you grow up in, the environmental toxins you breathe, the chronic stress your body absorbs, the quality of healthcare you receive, and even whether the medical devices used on you work correctly. None of these are genetic. All of them are structural.
This does not mean that every person of a given race will have the same health experience. Individual circumstances vary enormously. But at the population level, the patterns are clear and persistent. Race is not a social determinant of health in the way that income or education is, something that directly provides or restricts resources. It is the axis along which many of those determinants are organized. It determines who is more likely to be poor, more likely to live near a Superfund site, more likely to be undertreated for pain, and more likely to age faster at a cellular level. Addressing racial health disparities requires changing those systems, not just treating the diseases they produce.