Blood is the most precious gift that anyone can give to another person — the gift of life. A decision to donate your blood can save a life, or even several if your blood is separated into its components — red cells, platelets and plasma — which can be used individually for patients with specific conditions. Safe blood saves lives and improves health. Blood transfusion is needed for: women with complications of pregnancy, such as ectopic pregnancies and hemorrhage before, during or after childbirth; children with severe anemia often resulting from malaria or malnutrition; people with severe trauma following accidents; and many surgical and cancer patients. It is also needed for regular transfusions for people with conditions such as thalassaemia and sickle cell disease and is used to make products such as clotting factors for people with hemophilia.There is a constant need for regular blood supply because blood can be stored for only a limited time before use. Regular blood donations by a sufficient number of healthy people is needed to ensure that safe blood will be available whenever and wherever it is needed.
In the developed world, most blood donors are unpaid volunteers (voluntary non remunerated donors, VNRD) who donate blood for a community supply. In poorer countries, established supplies are limited and donors usually give blood when family or friends need a transfusion (directed donation). Many donors donate as an act of charity, but in some countries some are paid and in some cases there are incentives other than money such as paid time off from work. Donors can also have blood drawn for their own future use (autologous donation). Donating is relatively safe, but some donors have bruising where the needle is inserted or may feel faint.
Potential donors are evaluated for anything that might make their blood unsafe to use. The screening includes testing for diseases that can be transmitted by a blood transfusion, including HIV and viral hepatitis. The donor must also answer questions about medical history and take a short physical examination to make sure the donation is not hazardous to his or her health. Donors must wait for 90 days between whole blood donations.
The amount of blood drawn and the methods vary. The collection can be done manually or with automated equipment that only takes specific portions of the blood. Most of the components of blood used for transfusions have a short shelf life, and maintaining a constant supply is a persistent problem. Blood donations are divided into groups based on who will receive the collected blood. An ‘allogeneic’ (also called ‘homologous’) donation is when a donor gives blood for storage at a blood bank for transfusion to an unknown recipient. A ‘directed’ donation is when a person, often a family member, donates blood for transfusion to a specific individual. Directed donations are relatively rare when an established supply exists. A ‘replacement donor’ donation is a hybrid of the two and is common in developing countries such as Nepal In this case, a friend or family member of the recipient donates blood to replace the stored blood used in a transfusion, ensuring a consistent supply. When a person has blood stored that will be transfused back to the donor at a later date, usually after surgery, that is called an ‘autologous’ donation.
Blood is sometimes collected using similar methods for therapeutic phlebotomy, similar to the ancient practice of bloodletting, which is used to treat conditions such as hereditary hemochromatosis or polycythemia vera. This blood is sometimes treated as a blood donation, but may be immediately discarded if it cannot be used for transfusion.
An event where donors come to donate allogeneic blood is sometimes called a ‘blood drive’ or a ‘blood donor session’ or blood donation camp. These can occur at a blood bank, but they are often set up at a location in the community such as a shopping center, workplace, school, college, or house of worship. Donors are typically required to give consent for the process. All blood donors are asked questions about their medical history. If a potential donor does not meet the donation criteria, they are ‘deferred’. This term is used because many donors who are ineligible may be allowed to donate later.
Donors are screened for health risks that could make the donation unsafe for the recipient. Autologous donors are not always screened for recipient safety problems since the donor is the only person who will receive the blood. In Nepal, donors are examined for signs and symptoms of diseases that can be transmitted in a blood transfusion, such as HIV,STIs, and viral hepatitis. Screening may include questions about risk factors for various diseases, such as tatoo, travel to foreign country, blood transfusion before. The donor is also examined and asked specific questions about their medical history to make sure that donating blood is not hazardous to their health. The donor’s hemoglobin level is tested to make sure that the loss of blood will not make them anemic. Pulse, blood pressure, and body temperature are also evaluated.
Elderly donors are sometimes also deferred on age alone because of health concerns. The safety of donating blood during pregnancy has not been studied thoroughly, and pregnant women are usually deferred.