What is a blood transfusion?
Blood transfusion is
a medical treatment that replaces blood lost through injury, surgery, or
disease. The blood goes through a tube from a bag to an intravenous (IV)
catheter and into your vein.
When is a blood transfusion needed?
You may need a
blood transfusion if you lose too much blood, such as through:
If you have an illness in which your
bone marrow doesn't make enough blood, such as
aplastic anemia, you may need transfusions.
Is a blood transfusion safe?
Blood used for
transfusions in the United States is very safe and generally free from disease.
Donated blood is carefully tested and tracked. It is very rare to get a disease through a
Getting the wrong blood type by accident is the
main risk in a blood transfusion, but it is rare. For every 1 million units of blood transfused, getting the wrong blood type happens, at the most, 4 times.1
Transfusion with the wrong blood type can cause a severe reaction that may be
Some people bank their own blood a few weeks
before they have surgery. If they need a transfusion during surgery, they can
receive their own banked blood. This reduces the risk of disease and
transfusion reaction from donated blood.
If you have many blood
transfusions, you are more likely to have problems from
immune system reactions. A reaction causes your
body to form antibodies that attack the new blood cells. But tests can help
avoid this. Before you get a blood transfusion, your blood is tested to find
out your blood type. And the blood you will get in the transfusion is tested to
make sure it matches your blood.
You may have a mild allergic
reaction even if you get the correct blood type. Signs of a reaction
- Shortness of
- A fast heart
- Low blood pressure.
A mild reaction can be scary, but it rarely is dangerous
if it's treated quickly.
What are blood types, and why are they important?
The most important blood type classification systems are the ABO system and the
Rh system. A, B, AB, and O are the
blood types in the ABO system. Each type of blood in
the ABO system also has a positive or negative
Rh factor. For example, if you have "A+ blood," it
means your blood is type A in the ABO system and your Rh factor is
If you get blood in a transfusion that isn't the right
type, you may have a transfusion reaction. A mild transfusion reaction rarely
is dangerous, but you must get treatment quickly. A severe transfusion reaction
can be deadly.