Blood Types
Blood types help doctors determine which blood can be safely given to a patient. They are based on markers, called antigens, found on red blood cells and are inherited from your parents.
There are eight common blood types: A+, A-, B+, B-, AB+, AB-, O+, and O-. These are determined by the ABO system and the Rh (positive or negative) factor.
The ABO system includes two antigens: A and B. Type A blood has the A antigen, type B has the B antigen, type AB has both, and type O has neither. The Rh factor refers to whether the Rh protein is present. Rh-negative blood can be given to both Rh-negative and Rh-positive patients, while Rh-positive blood can only be given to Rh-positive patients.
A Positive (A+)
A+ is the second most common blood type in the United States, making up about 34% of the population. Patients with A+ blood can receive A+, A-, O+, and O- blood and can donate to A+ and AB+ patients.
Preferred donations: Platelets
A Negative (A-)
A- accounts for about 6% of the population. It can be given to all A and AB patients, while A- patients can only receive A- or O- blood.
Preferred donations: Whole Blood, Double Red Cells
B Positive (B+)
B+ blood is found in about 9% of the U.S. population. B+ patients can receive B+, B-, O+, or O- blood and can donate to B+ and AB+ patients.
Preferred donations: Platelets
B Negative (B-)
B- is rare, representing about 2% of the population. It can be given to B and AB patients of any Rh type. B- patients can only receive B- or O- blood.
Preferred donations: Whole Blood, Double Red Cells
O Positive (O+)
O+ is the most common blood type, accounting for about 38% of the population. O+ patients can receive O+ or O- blood. O+ blood can be given to all Rh-positive patients.
Preferred donations: Whole Blood, Double Red Cells
O Negative (O-)
O- makes up about 9% of the population. It is the universal red blood cell donor and can be given to patients of any blood type. O- patients can only receive O- blood.
Preferred donations: Whole Blood, Double Red Cells
AB Positive (AB+)
AB+ is one of the least common blood types, representing about 3% of the population. AB+ patients can receive blood from any blood type.
Preferred donations: Plasma, Platelets
AB Negative (AB-)
AB- is the rarest blood type, found in about 1% of the U.S. population. AB- patients can receive A-, B-, AB-, or O- blood.
Preferred donations: Plasma
Not sure what your blood type is? Your blood type is determined at your first donation, and your donation helps ensure lifesaving blood is available when it’s needed most.
