Blood Type Distribution in India
Updated May 2026
Reference summary
India has one of the highest B blood type frequencies in the world. The Bombay phenotype (hh) was first described in Mumbai in 1952 and remains concentrated in Maharashtra. Rh-negative is uncommon in Indian populations, putting particular pressure on Rh-negative donor recruitment. This page summarises the published distribution data and the implications for transfusion services. It is not medical advice.
National distribution overview
Estimates of national ABO and Rh-D distribution in India come from large blood-bank donor surveys and from population studies published in the Indian Journal of Medical Research, Asian Journal of Transfusion Science, and similar peer-reviewed venues. The widely cited approximate national average is: O-positive 37 percent, B-positive 32 percent, A-positive 22 percent, AB-positive 7 percent, with corresponding Rh-negative types at much lower frequencies (each typically under 2 percent).
These figures are estimates, not precise population census numbers. Donor populations under-represent the very young and the very old, and over-represent urban populations. Smaller community-level studies sometimes produce different numbers.
What the figures consistently show is the relatively high B prevalence (around 32 percent for B-positive) compared with global averages. In the United States, B-positive is around 8.5 percent of donors. In Sub-Saharan African populations, B-positive is around 19 percent. India sits at the high end of the global B distribution.
Why B blood type is so common in India
The high B allele frequency in South and Central Asia is a long-standing observation in human population genetics. The most likely explanation involves a combination of population history and balancing selection. The B allele appears to have arisen by mutation from the A allele several million years ago and has been maintained at high frequency in some populations by selective pressures, possibly involving differential resistance to infectious diseases.
Plasmodium falciparum (the malaria parasite) and other infectious agents have been hypothesised as selective pressures that may favour different ABO frequencies in different geographic regions. The exact selective forces remain a topic of research, but the descriptive observation (high B in South Asia, high A in Northern Europe, high O in Africa and the Americas) is well established.
Detailed molecular evolution studies are summarised in the 2008 Calafell et al. paper on ABO molecular evolution and in the International Society of Blood Transfusion reference literature.
Regional variation across India
Within India, blood type distribution varies substantially by state and region. North Indian and Western Indian states (Punjab, Haryana, Rajasthan, Gujarat, Maharashtra) generally show higher B frequencies. South Indian states (Tamil Nadu, Kerala, Karnataka, Andhra Pradesh) show somewhat lower B frequencies and higher O frequencies. Northeastern states with substantial Tibetan-Burman ancestry (Assam, Manipur, Mizoram, Nagaland) show patterns more similar to Southeast Asian populations.
Within-state variation is also substantial. Studies of specific community groups (Brahmin, Vaishya, tribal populations, urban populations) often show different ABO frequencies. The marriage and migration patterns over thousands of years have produced a population structure where blood type frequency is one of many traits that vary at fine geographic and community scales.
For specific local figures, the relevant regional blood transfusion centre or the latest peer-reviewed survey is the most reliable source. Generic national averages should be used cautiously when planning local transfusion services.
The Bombay phenotype
The Bombay phenotype (also called Oh or hh blood group) was first described by Bhende and colleagues in a 1952 paper in The Lancet. The discovery occurred in Mumbai (then Bombay) in patients whose blood typed as O but unexpectedly produced a transfusion reaction with O-type donor blood. Investigation revealed they lacked the H antigen, which is the precursor structure on which the A and B antigens are built.
People with the Bombay phenotype produce no A, no B, and no H antigen on their red cells. They have anti-A, anti-B, and anti-H antibodies in their plasma. They can only receive blood from other Bombay phenotype donors. Standard O-type blood (which carries H antigen) would trigger an anti-H reaction.
The Bombay phenotype occurs in approximately 1 in 10,000 people in India, with concentration in Maharashtra (the historical home of the original cases) and surrounding states. Outside India, it is much rarer. Bombay phenotype donors and recipients are managed through dedicated rare blood registers; the Indian Society of Blood Transfusion and Immunohaematology (ISBTI) coordinates the Indian register.
See our rare blood types page for the wider context of Rhnull, Vel-negative, and other rare blood types beyond the standard 8.
Implications for Indian transfusion services
The relatively high B frequency in India shifts the local blood bank inventory mix. Compared with US or UK blood services (where B is uncommon and B-negative particularly so), Indian blood services have larger B-type stocks and proportionally larger demand for B-compatible blood.
The low overall Rh-negative frequency creates a particular supply pressure for Rh-negative blood. Rh-negative women in pregnancy still need anti-D prophylaxis (see our anti-D immunoglobulin page), and trauma patients without known type still need universal donor blood. The smaller pool of Rh-negative donors must support this demand.
Voluntary blood donation in India has grown substantially since the 1990s, supported by the National Blood Transfusion Council, the National AIDS Control Organisation, and state blood transfusion councils. The shift from family replacement donation toward voluntary donation has been a major public health objective. The NBTC website covers current policy.
Donating blood in India
Eligibility for voluntary blood donation in India broadly follows international norms: age 18 to 65 (some centres extend to 70 with annual GP confirmation), minimum weight 45 kg, haemoglobin minimum 12.5 g/dL, no infection or recent vaccination contraindications. The donation interval for whole blood is 3 months for males and 4 months for females.
Major hospitals and blood banks across the country accept donors. The eRaktKosh portal lists registered blood banks and current stock by type. The Indian Red Cross Society and Lions and Rotary Clubs coordinate many donation drives. Apheresis platelet donation is increasingly available in larger urban centres.
For specific eligibility for your situation, contact your nearest registered blood bank. The deferral list is broadly similar to international standards.