A blood transfusion is the delivery of blood through a vein. The blood may come from an unrelated or related donor.

For planned procedures, some people have their blood drawn at an earlier date and stored until the transfusion is needed.

A blood transfusion should help increase your level of blood cells or other specific blood products. It may be needed if you have:

  • Blood and fluid loss due to injury, surgery, or disease
  • Severe anemia
  • Bleeding disorders, such as von Willebrand disease or hemophilia
  • Poor immune system
  • Leukemia
  • Diseases that result in destruction of blood cells or bone marrow
  • Side effects of certain medicines such as chemotherapy for cancer