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Blood Transfusion

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Topic Overview

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 blood transfusion.

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 life-threatening.2

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 include:

A mild reaction can be scary, but it rarely is dangerous if it's treated quickly.


WebMD Medical Reference from Healthwise

Last Updated: March 12, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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