Blood groups.
All eight groups, how rare each is, and who each can help.
12 guides
A negative blood group, rare and far-reaching
A− is found in under 1 in 100 Indians, yet its red cells help four patient groups. What A− means, who it saves, and why banks never have enough of it.
A positive blood group, the quiet workhorse
A+ is found in roughly 1 in 5 Indians. Who A+ red cells help, who can give to A+, the plasma note, and why routine demand makes A+ donors essential year-round.
AB negative, the rarest of the eight
AB− appears in roughly 1 in 250 Indians, and its donors are special twice over: rare red cells for rare patients, and universal plasma for everyone else.
AB positive, the universal recipient, and plasma's universal donor
AB+ is found in roughly 1 in 13 Indians. Its red cells fit only one group, but AB plasma fits everyone. The inversion that makes AB donations special.
B negative blood group, scarce where demand never stops
B− is found in roughly 1 in 90 Indians while B-group demand is enormous. The double squeeze on India's B− supply, explained plainly.
B positive blood group, the Asia story
B+ is one of India's most common groups (roughly 1 in 3 people) far more than in the West. The population genetics, who B+ helps, plasma inversion, and why demand is constant.
O negative blood group, the universal red cell donor
O− is the universal red cell donor: no A, B or D antigens, fits every patient in an emergency, and is always in shortage. Why O− matters, myths, and who can give to whom.
O positive blood group, India's backbone
O+ is the most common blood group in India, roughly 1 in 3 people. Who O+ red cells help, who can give to O+, why it isn't universal, and why demand never stops.
Rare blood groups in Assam, why negative donors matter most
O negative, A negative, B negative, AB negative, the groups banks always run short of, and why registers matter.
Rare blood types, Bombay phenotype, Rh-null and the registries that find them
What makes a blood type genuinely rare: Bombay phenotype, Rh-null golden blood, Kell-Duffy-Kidd combinations, and why rare donor registries matter.
The Rh factor, the + and − behind your blood group
What the Rh factor actually is, why Rh− donors matter so much, weak D, anti-D in pregnancy, and the emergency rules that keep patients safe.
Why is it called Rh? The rhesus monkey story
How blood research on rhesus macaques in 1937–1940 gave the Rh factor its name, explained transfusion reactions, and led to anti-D's lifesaving discovery.