If you have any other questions or concerns, please contact your doctor. Blood contains red and white blood cells and platelets which float in a liquid called plasma. Red blood cells contain haemoglobin and carry oxygen to all the parts of the body. White blood cells are used to fight infection. Platelets are used to prevent bleeding.
Plasma contains a variety of important substances, some of which also help to prevent bleeding.
Blood from a donor can be separated into components such as red blood cells, platelets, plasma and substances in plasma such as albumin and clotting factors. A transfusion occurs when you receive a particular blood component through a tube which is often hooked-up to a vein in your arm. Blood is collected from healthy volunteer donors. Blood is not used in transfusions if there are any concerns that it may transmit disease. Transfusions are necessary to replace certain blood components which are at low levels in your blood.