Blood transfusion

In a blood transfusion, donated blood is added to your own blood. A blood transfusion may also be done to supplement various components of your blood with donated blood products. In rare cases, a blood transfusion is done with blood that you've donated ahead of time before you undergo surgery.

During a typical blood transfusion, certain parts of blood are delivered through an intravenous (IV) line that's placed in one of the veins in your arm. A blood transfusion usually takes one to two hours, though in an emergency it can be done much faster.

A blood transfusion boosts blood levels that are low, either because your body isn't making enough or because blood has been lost during surgery, injury or disease.

Why it's done Risks How you prepare What you can expect Results

There are many reasons people receive blood transfusions, including surgery, injury and disease. Blood has several components, including red cells, white cells, plasma and platelets. You'll receive a transfusion that provides the part or parts of blood that will be most helpful for you. Whole blood means the blood contains all its parts, but whole blood is rarely used for transfusion.

Researchers are working on ways to develop an artificial blood, but so far there's no universally accepted replacement for human blood.

Surgery, injury or anemia

Loss of blood during surgery or as the result of injury may result in decreased red blood cells (anemia) and may require a transfusion of what's called packed red blood cells, meaning the blood given contains a concentration of mostly red blood cells. In addition, anemia from other causes may require a transfusion of packed red blood cells.


Cancer may decrease your body's production of red blood cells, white blood cells and platelets by impacting the organs that affect blood count, such as the kidneys, bone marrow and spleen. Drugs used in chemotherapy also can decrease components of the blood. Blood transfusions may be used to counter such effects.


Some illnesses cause your body to make too few platelets or clotting factors. You may need plasma or clotting factor transfusions to make up for low levels.

Infection, liver failure or severe burns

You may need a transfusion of plasma, the liquid part of blood.

Blood disorders

People with blood diseases, and those undergoing stem cell transplants as part of the treatment of such diseases, may receive transfusions of red blood cells and platelets.

Severe liver malfunction

A transfusion of albumin, a blood protein, may be given to help treat some severe liver problems.

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