29,000 patients are treated with blood or blood products in New Zealand each year.
Approximately 120,000 units of whole blood are collected every year in New Zealand.
Much of todays medical care depends on a steady supply of blood from volunteer donors.
Just one donation can help save the lives of up to three people.
One donation can be separated into several components (red blood cells, platelets and plasma) each of which are used to treat different types of patients, for example, accident and burns victims, patients undergoing surgery, adults and children suffering leukaemia, and transplant patients.
Large amounts of plasma are also needed to make special plasma protein concentrates.
When giving blood, approximately 470mL of blood will be donated (7% - 8% of the blood volume of an average adult, i.e. approx. 1.5 cans of soft drink), plus 15mL for test samples.
The body will replace the fluids of the donated blood in just 24 hours. The red blood cells will be replaced in about 6 to 8 weeks. After 3 months, a person can choose to donate again.
There are four main blood types A, B, AB and O in the ABO blood group system.
When you become a blood donor you will be advised of your blood group.
There are about one billion red blood cells in two or three drops of blood.
Red blood cells, white blood cells and platelets are constantly being made in your bone marrow.
The red cell component of blood must be transfused within 35 days of collection.
Platelets must be transfused within 7 days of collection.
Plasma can be frozen for up to two years and blood products made from plasma can be stored for up to two years.
People who have been in accidents and suffered massive blood loss may need multiple transfusions of red cell components.
The biggest use of blood products is for the treatment of cancer at 29% with the next biggest being accidents at 18%. Blood required for mothers and babies makes up 6%. People who have been in accidents and suffered massive blood loss may need multiple transfusions of red cell components.