What Are Blood Groups?
Blood groups are classifications of blood based on the presence or absence of specific antigens on the surface of red blood cells. These classifications are crucial for safe blood transfusions and medical procedures.
The ABO System
Main Blood Types
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Type A: Has A antigens on red cells and B antibodies in plasma
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Type B: Has B antigens on red cells and A antibodies in plasma
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Type AB: Has both A and B antigens on red cells; no A or B antibodies in plasma
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Type O: Has neither A nor B antigens on red cells; has both A and B antibodies in plasma
The Rh Factor
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Rh-positive (Rh+): Indicates presence of Rh factor
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Rh-negative (Rh-): Indicates absence of Rh factor
Clinical Significance
Transfusion Compatibility
- Type O-negative is the universal donor
- Type AB-positive is the universal recipient
- Incorrect matching can cause severe transfusion reactions
Pregnancy Considerations
- Important during pregnancy due to potential Rh incompatibility
- May require special monitoring if mother is Rh-negative
Distribution in Population
- Type O: ~44% of population
- Type A: ~42% of population
- Type B: ~10% of population
- Type AB: ~4% of population
Testing and Determination
- Simple blood test can determine blood type
- Usually tested at birth or before medical procedures
- Important for medical records and emergency situations