Where is blood type B most common?

September 22, 2025 •

4 min read

Globally, while O is the most prevalent blood type, certain populations exhibit a much higher frequency of type B blood. This phenomenon is largely concentrated in specific geographic regions, raising the question: Where is blood type B most common?

Quick Summary

Blood type B shows its highest prevalence across a broad belt of Eurasia, encompassing countries in Central Asia, the Indian subcontinent, and China, with frequency decreasing significantly further west. Its distribution is closely linked to ancient nomadic migration patterns and historic population movements.

Key Points

Prevalence in Asia: Blood type B is most common across a belt stretching from Central Asia through the Indian subcontinent and China, with some of the highest frequencies found in countries like India, Pakistan, and Bangladesh.
Origin in the Himalayas: The B allele is believed to have originated in the Himalayan highlands around 10,000–15,000 BCE, driven by changes in climate and diet.
Spread by Nomadic Tribes: Its wide geographic spread was primarily facilitated by the migrations of nomadic peoples, such as the Mongolians, who moved across the Eurasian plains.
Migration Pattern Reflected: The modern distribution pattern, with higher frequencies in the east and a gradual decline westward across Europe, mirrors these ancient human migration routes.
Health Correlates: Statistical studies suggest individuals with blood type B may have a slightly higher risk of cardiovascular diseases like heart attack and clotting issues compared to those with type O blood.
Evolutionary Adaptation: The existence of different blood types is thought to be an evolutionary advantage, with variations helping human populations survive different disease epidemics over time.

The Geographic Heartlands of Blood Type B

The distribution of blood type B is one of the most geographically distinct among the ABO blood groups. Unlike blood type O, which is more universal, or type A, which has high concentrations in Europe, type B is a hallmark of populations across a vast expanse of Asia and parts of Africa. This pattern forms a distinct “B-belt” stretching across the Eurasian continent.

Central and East Asia

India and Pakistan: These regions, particularly the Indian subcontinent, are home to some of the highest frequencies of blood type B in the world, with studies in some donor populations showing it nearly as common as type O. Statista specifically highlights Pakistan and Bangladesh as having a high share of B-positive types.
China and Mongolia: High concentrations of type B blood are found among the populations in these areas, especially in the north. Chinese donors, for example, have shown a B blood group frequency of up to 25% in some reports.
East and Southeast Asia: While frequencies vary, blood type B is also well-represented in many parts of Southeast Asia, with a high percentage seen in Indonesia, for example.

Eastern Europe and Africa

Eastern Europe: Traveling west from the Asian heartland, the prevalence of type B gradually declines. However, it remains more common in parts of Eastern Europe (like Hungary and Russia) compared to Western Europe, a legacy of historical migrations from the east.
Africa: Certain parts of Africa also exhibit a high frequency of blood type B. One study noted that blood group B was the most prominent in central and western Africa, contrasting with the higher prevalence of type O in the southern and eastern regions.

The Journey of Blood Type B: Migration and Adaptation

The geographical distribution of blood type B offers a compelling story about human migration and adaptation. Research suggests the B allele first appeared in significant numbers between 10,000 and 15,000 BCE in the Himalayan highlands, likely as an adaptation to climatic and dietary changes.

Nomadic Life and Diet: The emergence of blood type B is linked to the rise of nomadic, animal-herding cultures. These groups, like the Mongolians who swept across Eurasia, depended heavily on meat and cultured dairy products, and their movement facilitated the spread of the B gene.
Genetic Expansion: The migratory patterns of these nomadic peoples pushed the B allele westward, and its prevalence remains highest along these ancient routes. The gradual decrease in type B frequency across Europe serves as a genetic roadmap of these historical movements.
Linkage and Selection: The persistence of blood group B may have been influenced by natural selection. As populations adapted to new environments and diets, the B gene proved successful, possibly due to linkages with other genes affecting metabolism and immune responses.

For more information on blood group evolution, visit the National Center for Biotechnology Information at https://www.ncbi.nlm.nih.gov/.

Blood Type and Health: What the Research Suggests

Growing evidence suggests that a person’s blood type can influence their susceptibility to certain diseases and health conditions. This is not a deterministic factor, but rather a subtle influence on overall risk.

Comparing Health Factors by ABO Blood Type


Health Factor	Type B Individuals	Type A Individuals	Type O Individuals
Cardiovascular Risk	Slightly higher risk for blood clots, heart attacks, and heart failure compared to Type O.	Slightly higher risk for blood clots and heart disease compared to Type O.	Slightly lower risk for blood clots and heart disease.
Infection Susceptibility	Some studies link it to a higher incidence of gonorrhea, tuberculosis, and certain bacterial infections.	Associated with higher rates of stomach cancer and some infections like smallpox.	Some protection against the most severe effects of malaria, but higher risk for cholera and plague infections.
Chronic Conditions	Some research indicates a higher risk for Type 2 diabetes and hypertension.	Associated with higher rates of stomach and pancreatic cancers.	Lower risk for Type 2 diabetes compared to other types.

It is crucial to remember that lifestyle, genetics, and environment play a much larger role in determining individual health than blood type alone. These are statistical associations found in large populations, not individual diagnoses.

Conclusion

The high prevalence of blood type B in Central Asia, India, and China is a direct result of ancient migratory patterns, particularly those of nomadic peoples who spread the gene across the Eurasian landmass. This distribution pattern, shaped by thousands of years of human history, underscores the remarkable interplay between our genetics, environment, and ancestral movements. While blood type B carries certain statistical health correlations, it remains a testament to the adaptability and diversity of the human species across the globe.

Frequently Asked Questions

Countries in Central and East Asia, including India, Pakistan, Bangladesh, and China, have some of the highest percentages of blood type B worldwide. In India and Pakistan, it is nearly as prevalent as blood type O in many populations.

Yes, research shows that blood type B is significantly more common in populations of Asian and African descent. For example, in the United States, Asian Americans and African Americans have a higher prevalence of blood type B compared to Americans of European descent.

The B allele is believed to have spread through human migration, most notably by nomadic peoples who moved across the Eurasian landmass. The pattern of its prevalence across different regions reflects the paths of these ancient migrations.

Blood type B is less common in Western Europe than in Asia, with its frequency generally decreasing the further west you go. However, it is more prevalent in Eastern European countries like Hungary and Russia due to historical population movements from the east.

The B allele is thought to be a relatively recent genetic mutation, emerging around 10,000–15,000 BCE in the Himalayan highlands. It spread with the movement of nomadic tribes, who were exposed to new environmental and dietary conditions.

Studies have shown some statistical correlations, though they are not definitive. Individuals with blood type B may have a slightly higher risk for blood clots and certain infectious diseases compared to type O, while type O may offer some protection against severe malaria.

Like all blood types, B positive is significantly more common than B negative. Globally, only about 7% of the population is Rh negative, meaning the Rh positive variant is far more prevalent in all blood groups, including type B.