A blood transfusion is the shift of blood or any of its parts from one person to another. Examples of parts of the blood that may be given are red blood cells, plasma, and clotting factors. Which part of the blood is given depends on the problem being treated.

When are blood transfusions needed?

A blood transfusion may be done when your life is threatened by blood loss or blood destruction by illness, or when you are not making enough blood. You may need a blood transfusion if you:

* are seriously injured

* are having surgical procedure

* have a blood disorder.

Blood circulates through the body, bringing oxygen and nutrients to every cell. Red blood cells carry oxygen. The most common reason for a transfusion is to help your body get enough oxygen by making sure you have enough red blood cells.

How is the blood given in a transfusion?

Blood is given to you through a needle in your vein. The amount of blood you need depends on how much you have lost or, if you have a blood disorder, how severe the disorder is. Your pulse, blood pressure, and temperature are watched while you receive blood. If you have a reaction while having a transfusion, the procedure is stopped. A reaction to a blood transfusion may include fever, chills, rash, a burning feeling along the vein where the transfusion is given, flushing, and headache. It is rare to have a severe reaction.

Is the donated blood safe?

Blood donated in the US is quite safe because it is very carefully tested before it is used for transfusions. The testing makes it very unlikely that you will receive infected blood. However, if a blood donor became infected with HIV within 2 weeks before donating blood, the HIV virus cannot be detected in the blood. This means there is always the slight chance that a blood transfusion will accidentally infect someone receiving blood. The chance of a blood donation having undetectable HIV is less than 1 in 2 million. The chance of getting HIV from donated blood is lower now than in past years because of improved lab tests of donated blood. Better screening of blood donors and donated blood also continues to reduce the risk of getting other infections, such as hepatitis, syphilis, or malaria, from a transfusion.

The safest blood is your own. If you are going to have an operation that may require a blood transfusion, it may be possible to recycle your blood during the surgical procedure. Another choice may be to donate your own blood ahead of time. Ask your surgeon if this is an option for you.