O-

O negative

ABO group O · Rh negative
Written by the VitaWhat editorial team · Medically reviewed by Steve Davis · Last reviewed 19 July 2026 · Editorial policy

The "universal donor" for red blood cells — no A, B or Rh antigens.

13%
UK population
3%
World population
All blood types
Can donate red cells to
O−
Can receive from

Key facts

  • Universal red-cell donor — can be given to anyone in an emergency
  • Used when a patient\'s blood type is unknown
  • Always in short supply relative to demand
  • Rarer worldwide than in the UK

Sources & references

  1. NHS Blood and Transplant — Blood types
  2. American Red Cross — Blood types

Related entries

O positiveA negativeA positiveAB negativeAB positiveB negative
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