What is a blood transfusion?
A transfusion is a medical procedure that adds a blood component directly to the bloodstream to correct a deficiency. Each year, Puget Sound Blood Center provides blood and laboratory services for more than 220,000 transfusions.

Transfusions may be needed by patients as part of treatment for:

• bleeding due to surgery or injury.
• inherited blood disorders.
• leukemia or other forms of cancer.
• organ or bone marrow transplantation.
• other conditions.

Blood is made up of several parts, or components:

• red blood cells carry oxygen to tissues or organs.
• platelets promote blood clotting.
• plasma (the fluid part of blood) carries blood cells throughout the body and contains proteins essential for blood clotting.
• white blood cells fight infection.
• cryoprecipitate (made from plasma) is a concentration of a clotting factor (fibrinogen) essential for blood clotting.

One or more of the above blood components may be required during treatment.