During blood transfusion
Learn about what happens during the blood transfusion.
Last updated 13 March 2026
During blood transfusion
Understand how a blood transfusion is done, and how long the whole process will take.
How it is done
A blood transfusion is usually given through a small tube inserted directly into a blood vessel in the arm.
How long will it take
On average, it takes about two to three hours for each unit of red cells to be transfused, and about 20 to 30 minutes for each unit of platelets or plasma.
Due to the risk of bacterial infection or deterioration of the blood components when they are exposed to room temperatures, transfusion of each unit should not take more than four hours.
Patient monitoring
A nurse will monitor your temperature, pulse and blood pressure before the start of the transfusion. This will continually be monitored during the transfusion.
You should notify the nurse immediately if you feel unwell or become uncomfortable during or just after the transfusion.