A blood transfusion involves receiving donated blood or blood products intravenously. Blood transfusions are most commonly used in situations where the patient has suffered significant blood loss, and to treat severe anemia or blood disorders.
Donated blood is often separated into its components:
Each unit of blood usually takes 2-3 hours to transfer into the patient's bloodstream. A unit of plasma or platelets generally takes 30-60 minutes.
Blood transfusions are used in a variety of situations, including:
Donors should be carefully selected, and the donated blood should be carefully screened for blood group, disease and pathogens. Unfortunately this screening is not so strict in some countries, so blood transfusion carries a higher risk of acquiring diseases such as hepatitis B or C, HIV/AIDS, or syphilis.
In very severe cases, blood transfusion may be necessary.