Every person has one of the following blood types: A, B, AB, or O. Also, every person's blood is either Rh-positive or Rh-negative. So, if you have type A blood, it's either A positive or A negative.
The blood used in a transfusion must work with your blood type. If it doesn't, antibodies (proteins) in your blood attack the new blood and make you sick.
Type O blood is safe for almost everyone. About 40 percent of the population has type O blood. People who have this blood type are called universal donors. Type O blood is used for emergencies when there's no time to test a person's blood type. People who have type AB blood are called universal recipients. This means they can get any type of blood. If you are Rh-positive, you can get Rh-positive or Rh-negative blood. Rh-negative is used for emergencies when there's no time to test a person's Rh type.
The blood used in a transfusion must work with your blood type. If it doesn't, antibodies (proteins) in your blood attack the new blood and make you sick.
Type O blood is safe for almost everyone. About 40 percent of the population has type O blood. People who have this blood type are called universal donors. Type O blood is used for emergencies when there's no time to test a person's blood type. People who have type AB blood are called universal recipients. This means they can get any type of blood. If you are Rh-positive, you can get Rh-positive or Rh-negative blood. Rh-negative is used for emergencies when there's no time to test a person's Rh type.