About Blood

Blood Facts & Blood History


Blood Facts

Each year about 15.7 million units of whole blood and red blood cells are donated in the United States by approximately nine million volunteer blood donors. These units are transfused to about four million patients per year. Blood Centers of the Pacific provides blood for a population of more than 2.2 million. To do this, we need to collect approximately 500 pints of blood daily.

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Needing Blood

Every day in the United States, approximately 41,000 units of blood are needed by patients.
More than 21 million units of blood components are transfused annually.

In order to assure that patients who need blood can have access to it immediately, there must be a ready supply on hospital shelves. After natural disasters and other tragedies, people tend to donate more blood. However, it is the people who donate regularly whose blood saves lives during emergency situations because it is there waiting on the hospital shelves.

Major Reasons Patients Need Blood

  • Cancer treatment
  • Heart and blood vessel disease
  • Disease of the gastrointestinal tract
  • Emergencies such as auto accidents and burns
  • Surgery, Organ transplant, Marrow transplant
  • Blood disorders such as anemia and hemophilia; sickle cell disease and thalassemia

When are blood donors needed most?

While blood donors are needed throughout the year, they are most needed during holidays and in the summer. It is during these times that the number of donations declines while the demand continues or even increases.

Who donates blood?

Although an estimated 38 percent of the U.S. population is eligible to donate blood at any given time, less than 10 percent do so annually. According to studies, the average donor is a college-educated white male, between the ages of 30 and 50, who is married and has an above-average income. However, a broad cross-section of the population donates every day. Furthermore, these “average” statistics are changing, and women and minority groups are volunteering to donate in increasing numbers. While persons 65 years and older compose 13 percent of the population, they use 50 percent of all blood units transfused.

Patients scheduled for surgery may be eligible to donate blood for themselves, a process known as autologous blood donation. In the weeks before non-emergency surgery, an autologous donor may be able to donate blood that will be stored until the surgical procedure.

What is the most common blood type?

The approximate distribution of blood types in the US population is as follows:

O positive O negative B positive B negative A Rh-positive AB Rh-positive A Rh-negative AB Rh-negative
39% 9% 9% 2% 31% 3% 6% 1%

O Negative red blood cells can be given to anyone in an emergency. Therefore people with type O negative blood are known as “universal donors.”

Type AB individuals can receive red blood cells of any ABO type. Those with type AB blood are known as “universal recipients.” In addition, AB Plasma donors can give to all blood types.


Blood Safety

The blood supply in the United States is much safer today than ever before. The risk of HIV transmission has been nearly eliminated and the risk of hepatitis transmission greatly reduced thanks to multiple levels of safeguards, including:

  • Donor screening
  • Blood testing
  • Donor deferral lists
  • Quarantine
  • Problems and Deficiencies

These procedures are followed by all blood centers nationwide and are monitored under the regulatory guidance of the U.S. Food and Drug Administration (FDA). The FDA regulates and licenses all blood banks. To learn more about federal policies related to blood, the latest in research and other important national information, visit the FDA’s Blood FAQs.

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What tests are performed on donated blood?

Donated blood is tested for ABO group (blood type) and Rh type (positive or negative), as well as for any unexpected red blood cell antibodies that may cause problems in the recipient. Screening tests also are performed for evidence of donor infection, such as hepatitis viruses B and C, human immunodeficiency viruses (HIV) 1 and 2, human T-lymphotropic viruses (HTLV) I and II, syphilis, West Nile Virus and T.cruzi infection. The specific tests performed are listed below:

  • Hepatitis B surface antigen (HBsAg)
  • Hepatitis B core antibody (anti-HBc)
  • Hepatitis C virus antibody (anti-HCV)
  • HIV-1 and HIV-2 antibody (anti-HIV-1 and anti-HIV-2)
  • HTLV-I and HTLV-II antibody (anti-HTLV-I and anti-HTLV-II)
  • Syphilis antibody
  • Trypanosoma cruzi antibody (Chagas Disease)
  • Nucleic Acid Amplification Testing (NAT) for HIV, Hepatitis B, Hepatitis C and West Nile Virus
  • Nucleic Acid Test (Investigational) for Zika Virus

Any unit of blood that shows evidence of carrying a disease is discarded and the donor is deferred from subsequent donation.


Blood History

The first recorded successful human blood transfusion was accomplished in 1818, but due to the lack of knowledge and research, it was followed by many blood transfusion failures.

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Some 80 years later, it was discovered that inherited differences in people’s red cells were the cause of many of the incompatibilities seen with transfusions. Four blood types were identified – A, B, AB and O. This discovery revolutionized hematology and led the way for successful blood transfusions.

During World War I, when human blood was needed for transfusions for wounded soldiers, scientists began to study how to preserve and transport blood. But it was not until World War II that the development of effective preservative solutions made blood transfusions widely and safely available. Since then, there have been many advances, such as the discovery of the Rh blood group system and technical developments such as the introduction of the plastic bag for safer blood collection.

By the end of 1947, several blood banks had been established in major cities across the United States and blood donation was promoted to the public as a way of fulfilling one’s civic responsibility.

Freezing of red blood cells, separation of different blood components by centrifugation, apheresis (extraction of one blood component and returning the rest to the donor) and many other discoveries and advancements make for full utilization of every donation. Each blood element can be used to treat different diseases.

Today, in light of HIV, Hepatitis C and many other diseases, the federal government has enforced regulations for blood screening tests in an effort to improve blood safety and to reduce the risk from blood transfusions. To further ensure the safety of the blood supply, the government outlawed paying someone for his or her blood.

Human blood is precious. There is no substitute for it and there is no way to manufacture it outside the body. Yet, millions of times each year, human blood is required to save the lives of people suffering from disease or who are victims of accidents.

That is why Blood Centers of the Pacific plays such a vital role in helping save lives in our community.

Data provided by the Department of Health & Human Services for 2011.