Rare groups
Bombay Blood Group: Why Rare Donor Networks Matter
The group that can only receive from itself.
What Bombay (hh/Oh) is
Discovered in Bombay in 1952, the hh phenotype lacks the H antigen that normal ABO groups build on — routine typing often misreads it as O, but Oh patients can receive ONLY Oh blood.
The arithmetic of one in a million
Prevalence is roughly 1 in 10,000 in parts of India (higher than elsewhere, but still vanishing) — a city may hold a handful of known donors, making registries literally life-or-death.
Networks are the only answer
No bank stocks Oh routinely. Cases are solved by calling known donors across cities — which is why every identified Oh individual should be on a registry like HelpALife's rare-group support.
Frequently asked questions
How is Bombay group detected?
Serum typing during cross-match reveals it — often discovered only when a transfusion is first needed.
I'm Oh — what should I do today?
Register, inform family (it's inherited), and consider pre-donating for yourself before planned surgeries.
Related guides
Why O Negative Blood Is So Important
Why Rare Blood Group Donors Should Register
How to Build a Rare Blood Donor Registry
How to Find Blood Donors Near You in an Emergency
How HelpALife Connects Blood Requests with Nearby Donors
Why You Should Bookmark a Blood Donor Platform Before an Emergency
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