Blood groups

Rare blood groups in Assam, why negative donors matter most

Creator: Assam Blood Donor team
Published: 2026-08-26

O negative, A negative, B negative, AB negative, the groups banks always run short of, and why registers matter.

In India, negative blood groups are rare: O− is well under 1 in 30 people; AB− about 1 in 250. That makes negative patients the hardest to serve in an emergency, and negative donors the most valuable people on any register. O− is the universal red-cell donor: every patient can receive O− in a crisis. When a bank says “we have nothing left”, it usually means O−. If your group is negative:

You may be the only match a negative patient in your district has.
Consider registering even if you donate rarely, emergency pings are infrequent and you can always decline.
Learn your group if you don’t know it: free at any camp. Explore your group: O− · A− · B− · AB−

People also ask

Which is the rarest blood group in India?

AB negative, roughly 1 in 250 people. All negative groups are short in Assam's banks because negatives can only receive from negatives.

Why are negative blood groups always short?

Fewer donors have them, and every negative patient must be matched with a negative donor. A small pool meets every negative emergency.

Can O negative blood be given to anyone?

Yes, O negative red cells suit every patient, which is why O− stock empties first in emergencies. O− patients, though, can only receive O−.

About this article

Written by Assam Blood Donor team. Medical review: pending, content follows published national (NBTC/NACO) guidance and is for general education, not personal medical advice. Last updated 26 Aug 2026.

Sources: National Blood Transfusion Council (NBTC) guidance · NACO Voluntary Blood Donation Programme · Assam SBTC donor criteria