Blood Types and Transfusions

In 1909, the four major blood types were discovered, and finally doctors understood why some transfusions were successful and others were not.

The four main blood types were A, B, AB and O. In addition, there are 300+ other blood types that affect how blood interacts with the body. The only other factor key to blood transfusions is the Rh factor, which can either be positive or negative.

The donation matching varies whether you are donating just red blood cells, the whole blood or the plasma. The "more complete" the blood you donate, the more sensitive the receipient's body is to the rest of the "stuff" it is getting pumped into it - and the more specific the match has to be.

In essence, if your body's blood has a Type A surface membrane, your body recognizes Type A to be an "OK thing in your body" and does not attack it. But if a cell of Type B comes along, that Type B membrane is NOT recognized, and the body attacks it as a foreign substance, just as it would attack a bacteria.


Blood Type
of Recipient

Donor Can Be for.....

Red Cells

Whole Blood


O + O +; O - O +; O - any O; A; B or AB
O - O - O - any O; A; B or AB
A + any
A +; A -;
O + or O -
any A + or A - any A or AB
A - any
A - or O -
A - any A or AB
B + any
B +; B -;
O + or O -
any B + or B - any B or AB
B - any
B - or O -
B - any B or AB
AB + any
AB +; AB -;
A +; A -;
B +; B -;
O +; or O-
any AB + or AB - any AB
AB - any AB -;
A -; B -, or
O -

More about Blood Types
Blood Types, Inheritance and Paternity
Blood Type Distributions Around the World
Blood Types and Illnesses
Important Types of Blood
The Basics of Blood
Evolution of Blood Types

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