Almost all of the blood used for blood transfusions is donated by volunteers.
For details on the donation process, see Donating Blood.
Safety of donated blood
The process of blood donation and the handling of donated blood in the United States is regulated by the U.S. Food and Drug Administration (FDA). The FDA enforces five layers of overlapping safeguards to protect the blood supply against disease.
Donor screening. To donate blood, you must answer a series of questions about your current health, health history, any travel to countries where certain diseases are common, and behavior that increases your risk for getting certain diseases, such as drug use or unprotected sex. Your temperature, your blood pressure, and the volume of red blood cells in a blood sample (hematocrit) are checked. You may not be allowed to donate blood if any of these screening steps suggests a problem, such as potential exposure to an infectious disease or anemia.
Deferred-donor lists. Organizations that collect blood must keep lists of people who are permanently prevented from giving blood. Potential donors must be checked against this list so that blood is not collected from them. The deferred-donor list includes people who have had certain types of cancer, had hepatitis after age 11, or are at high risk for HIV infection.
Blood testing. After donation, every unit of blood is tested for certain diseases, such as hepatitis B and C, HIV, West Nile virus, syphilis, and HTLV-I/II viruses. If any disease is detected, the blood is thrown away.
Quarantine. Donated blood is kept isolated from other blood and cannot be used for any purpose until it passes all required tests.
Quality assurance. Blood centers must keep careful records of every unit of donated blood. If a problem arises involving a donated unit of blood, the blood center must notify the FDA and work with them to correct the problem.
Donating blood for your own use
If you are going to have surgery and expect to need a blood transfusion, you may want to consider donating or banking your own blood before the surgery (autologous donation).
For more information on this option, see:
Blood Transfusions: Should I Bank Blood Before Surgery?