"Blood types are inherited and determine who you can give blood to and receive blood from. The type of blood donation that is best for you is determined by your blood type, as well as patient need.
What makes blood types different? There are four major blood groups determined by the absence or presence of specific proteins called antigens, found on the surface of red blood cells and antibodies in the plasma. You"ve probably heard of people being Rh Positive or Negative as well. In addition to the A and B antigens, there is a protein called the Rh factor, which can be either present ( ) or absent (), creating the 8 most common blood types (O , O-, A , A-, B , B-, AB , AB-). Each blood type is unique and special. These types must be properly matched for a blood transfusion to work."