What are transfusions?

Having a transfusion means getting blood or some part of it. Transfusions of blood and blood products temporarily replace parts of the blood when a person has been bleeding, or when their body can’t make enough blood. Blood transfusions save millions of lives in the United States every year.

Sometimes, a person will need transfusions after an injury or surgery, or if they have cancer or certain other diseases. The blood will usually come from another person, called a donor.

People usually donate whole blood, but whole blood transfusions are rarely used. Blood has many parts (components), such as red blood cells, white blood cells, platelets, plasma, clotting factors, and small proteins, and each component has a different job. After it’s donated, whole blood is usually separated into components. This lets doctors give patients only the part they need. It also helps to get the most out of the donated blood supply.

Transfusions are given into a vein, through an intravenous (IV) line.