About Blood Types

Blood Types Graphic

Blood Types

Does everyone have the same blood?

No, there are eight different blood types: A positive, A negative, B positive, B negative, AB positive, AB negative, O positive and O negative. Your parents’ blood types determine which blood type you have.

Donations from all blood types are important. Some blood types are not compatible, and hospitals must give the correct blood type in a transfusion. Using the wrong blood type can cause serious health problems or even death. This is why we need supplies of each blood type on hand.

KBC offers a number of donation types, including whole blood, double red or platelets

Is One Blood Type More Valuable Than Another?

Donations of all blood types are needed to help save lives. Sometimes a particular blood type will be in short supply and donations for that blood type will be urgently needed.

Type O negative, often called the “universal” blood type, is almost always in demand because O negative red blood cells can be transfused to anyone regardless of their blood type.

People with Type AB blood are universal plasma donors because their blood plasma can be used by anyone. Blood plasma is used to help trauma and burn victims, people with clotting problems, leukemia patients and many others. This is the rarest blood type, occurring in only 5% of the population.

Your donation of red blood cells, platelets, or plasma can make a lifesaving difference for someone in our community. While all blood types are needed, some are more conducive to particular types of blood donations, such as platelets or double red cells. Ask your phlebotomist what’s the best way you can save a life.

The Eight Main Blood Types


7% of the population

Universal blood type (red blood cells can be transfused to anyone)

O- patients can only receive O- blood

Often used in emergencies/traumas when patient's blood type is unknown

Key for treating babies and patients with weakened immune systems

Always in high demand  


39% of the population

Most common blood type

Given to patients more than any other blood type

More than 80% of the population has a positive blood type and therefore can receive O+

O+ patients can only receive O+and O- red blood cells


6% of the population

In emergencies, doctors depend on type A and AB plasma for trauma patients and accident victims

Can donate to type A or AB regardless if they are positive or negative

A- patients can only receive A- or O-, just 13% of the population


32% of the population

Second-most common blood type

In high demand to treat cancer patients and premature babies

In emergencies, doctors depend on type A and AB plasma for trauma patients and accident victims

A+ patients can receive A, O+ and O-


2% of the population

Often transfsued in only three days after donation

Can be given to both B and AB patients

B- patients can only receive types B- and O-, only 9% of the population


11% of the population

B+ platelets are in high demand because anyone can use them (except childbearing-aged females of types O-, A-, B- and AB-)

B+ and AB+ can receive B+ red cells 

Type B and O can receive B+ plasma

B+ can receive positive and negative red cells of both B and O types


1% of the population

Least common blood type

Only patients with AB+ or AB- can receive AB- red cells

Anyone can receive AB- plasma and platelets

AB plasma is especially needed for emergencies, for babies and for those with weakened immune systems


4% of the population

Considered universal recipient because AB+ patients can receive red blood cells form all blood types

AB plasma can be used for any patient

AB plasma is especially needed for emergencies, for babies and for those with weakened immune system

Rare and Uncommon Blood Types

Fda Review

While most people fit into the eight blood groups, not everyone fits into those main types. There are more than 35 other blood groups and more than 600 other known antigens.

Matching matters, and whether you fall into one of the main eight blood groups or have a special mix of proteins and sugars (antigens) that give you a rare blood type, KBC is committed to ensuring blood is available for every type of blood. 

To learn more about rare and uncommon blood types, click below. 

Rare Blood Types Rare Blood Types

Current Blood Supply Levels by Blood Type

o+ 75%

o- 50%

a+ 75%

a- 25%

b+ 50%

b- 50%

ab+ 75%

ab- 50%