How long does it take for a blood transfusion?

Mayo Clinic reports that blood transfusions typically take one or two hours depending on which parts of blood and how much blood the patient receives. Patients typically sit or lie down during the procedure.

California Pacific Medical Center notes on its website that the purpose of blood transfusions is to increase certain components in the bloodstream including plasma, platelets, red blood cells or whole blood. A transfusion replaces blood that is lost or lessened due to cancer, surgery, injury or other causes.

Patients may need more blood testing after the procedure, states Mayo Clinic, to determine how well the body is incorporating the new blood and to ensure that levels of blood components are correct.