Blood Type Distribution by Ethnicity and Country
Blood type frequencies vary significantly across ethnic groups and geographic regions. O-positive is the most common type worldwide, but the proportions shift dramatically between populations. Updated April 2026.
Why Blood Type Distribution Varies
ABO blood group frequencies in human populations are not uniform - they vary substantially by ethnicity and geographic origin. These differences are the result of evolutionary genetic pressures, population bottlenecks (where a small group founded a larger population, carrying their blood type proportions), and possibly disease resistance advantages.
The B allele, for example, is significantly more common in South Asian and Central Asian populations, making B blood group far more prevalent in India and Pakistan than in Western Europe or the Americas. In Japan, the A allele is particularly common, leading to higher A-type frequencies. Sub-Saharan African populations have very high O frequencies.
Rh-negative status also varies by ethnicity. In European populations, about 15% are Rh-negative. In Asian and African populations, Rh-negative is rare - often under 1%. This means Rh-negative blood types (like O-, A-, B-, AB-) are predominantly a European genetic trait.
US Blood Type Distribution by Ethnicity
| Ethnic group | O+ | O- | A+ | A- | B+ | B- | AB+ | AB- |
|---|---|---|---|---|---|---|---|---|
| White / Caucasian | 37% | 8% | 33% | 7% | 9% | 2% | 3% | 1% |
| African American | 47% | 4% | 24% | 2% | 18% | 1% | 4% | <1% |
| Hispanic / Latino | 53% | 4% | 29% | 2% | 9% | 1% | 2% | <1% |
| Asian / Pacific Islander | 39% | 1% | 28% | 0.5% | 25% | 0.4% | 7% | 0.1% |
| Native American | 57% | 1% | 31% | 3% | 8% | 0.5% | 1% | <1% |
Source: American Red Cross, Stanford Blood Center. Values are approximate percentages based on US blood donor data. Donor populations may not be fully representative of the general population.
Blood Type Distribution by Country
| Country | O+ | A+ | B+ | AB+ | O- | A- | B- | AB- |
|---|---|---|---|---|---|---|---|---|
| United States | 37% | 36% | 8.5% | 3% | 6.6% | 6.3% | 1.5% | 0.6% |
| United Kingdom | 36% | 30% | 8% | 3% | 7% | 8% | 2% | 1% |
| India | 37% | 22% | 32% | 7% | 2% | 0.8% | 1% | 0.2% |
| Japan | 30% | 40% | 20% | 10% | <1% | <1% | <1% | <1% |
| Nigeria | 57% | 20% | 19% | 3% | 1% | <1% | <1% | <1% |
| Brazil | 44% | 33% | 9% | 3% | 6% | 3% | 1% | <1% |
Approximate values based on published population genetics studies and national blood service data. Country-level data is approximate and varies by region within each country.
Why Ethnic Matching Matters for Rare Blood Types
For most transfusions, ABO and Rh compatibility is sufficient. However, patients who require frequent transfusions - especially those with sickle cell disease, thalassaemia, or other haematological conditions - can develop antibodies to minor blood group antigens after multiple transfusions. Once sensitised, subsequent transfusions must avoid not just ABO/Rh mismatches but also mismatches in systems like Duffy, Kell, Kidd, and MNS.
Because minor antigen frequencies vary by ethnicity, patients from a specific ethnic background are more likely to find matched donors from within the same ethnic community. This is why American Red Cross and other blood banks specifically recruit donors from ethnic communities that are underrepresented in the donor pool - not to segregate blood, but to ensure patients from those communities can receive closely matched units.
Sickle cell disease predominantly affects patients of African, Caribbean, Mediterranean, Middle Eastern, and Asian origin. These patients require chronic transfusions and benefit enormously from donors who share their minor blood group antigens. Increasing diversity in the donor pool directly reduces the risk of sensitisation in these patients.