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Blood Transfusion Information

Article Translations: (Spanish) (Somali)

Sometimes during medical treatment, transfusions of blood or blood products are needed. This sheet explains what you should know about blood transfusions.

How will I know if my child needs a transfusion?

The doctor will discuss the need for transfusion with you before it is given. This is a chance to discuss your questions and concerns with the doctor before you agree to a blood transfusion for your child. However, in an emergency, the doctor may have to decide whether to transfuse before talking to you.

Why would my child need a blood transfusion?

  • to increase the number of red blood cells that carry oxygen in the blood
  • to replace blood lost from an injury, during surgery, or due to a medical condition
  • to replace needed blood components
  • to control bleeding

What kinds of blood products are there and how are they used?

Donated blood (whole blood) is divided into several products:

  • Packed red blood cells – the red blood cells carry oxygen from the lungs to the body. They may be given for rapid bleeding or anemia (low red blood cell numbers).
  • Plasma is the fluid portion of blood that is separated from the red blood cells and frozen for later use. Plasma contains coagulation factors that help control (stop) bleeding.
  • Platelets help stop bleeding by combining with thrombin to form a clot at the bleeding site.
  • White blood cells are rarely transfused, but may be given to patients with infections and very low white blood cell counts.

How safe is the blood supply?

The American blood supply is the safest in the world. Blood is donated by volunteers. Before giving blood, donors must answer questions about their health and risk factors for disease. Only a healthy person can give blood.

Every donation is tested, according to federal requirements, for the following diseases:

  • hepatitis B and C
  • human immunodeficiency virus types 1 and 2 (HIV, the AIDS virus)
  • human lymphotrophic virus, types 1 and 2
  • syphilis

Before the transfusion, the donor blood is tested against the patient's blood to be sure they match.

What are the risks?

Even though the blood supply is very safe, all blood transfusions have a small chance of causing problems. However, the risks of not receiving blood outweigh the risks of transfusion.

Average risk for each unit of blood transfused:

  • Rash, hives, itching: less than 3%
  • Fever: less than 1%
  • Hemolysis (breakdown of red blood cells): 1 in 76,000
  • Hepatitis C: 1 in 1 million
  • Hepatitis B: 1 in 200,000 (Hepatitis B can be prevented by getting the hepatitis B vaccine.)
  • HIV (the AIDS virus): 1 in 2 million
  • Bacterial contamination causing a life-threatening infection: 1 in 1 million
  • Cytomegalovirus: by removing the white blood cells (leukoreduction) from the red blood cell and platelet units, we lower the risk of cytomegalovirus transmission and prevent recurrent, nonhemolytic transfusion reactions
  • Transfusion related acute lung injury: 1:1,200 to 1:190,000


This sheet is not specific to your child but provides general information. If you have questions, please ask the doctor.

Information about blood transfusions is also available from our local blood supplier, Memorial Blood Center as well as from your doctor's office, the nurse, or the Transfusion Service at 612-813-6824.

Reviewed 5/2024

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This page is not specific to your child, but provides general information on the topic above. If you have any questions, please call your clinic. For more reading material about this and other health topics, please call or visit Children's Minnesota Family Resource Center library, or visit

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