What is a blood transfusion?
A transfusion is a medical procedure to correct a deficiency of blood or its parts. A person requiring a transfusion may need whole blood or blood components added directly to the bloodstream. Each month, the Puget Sound Blood Center provides blood and laboratory services for more than 20,000 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

Blood is made up of several parts, or components:

• Red cells carry oxygen to tissues or organs
• Platelets promote blood clotting
• White cells fight infection

Plasma (the fluid part of blood) carries blood cells throughout the body and contains proteins essential for blood clotting.