ASBP: About Blood - Why blood and donors are so important
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Did you know that blood can be separated into three main components – red blood cells (RBCs), platelets, and plasma? Read more to find out about blood and why regular blood donors are so important.

What’s in a blood group and type?

Blood Group
Did you know that there are four different blood groups?: A, B, AB, and O. A person's blood group is distinguished by tiny markers known as antigens which cover the blood cell surface. Below is a simple breakdown of blood groups and antigens.
  • Group A blood has A antigens
  • Group B blood has B antigens
  • Group AB blood has both A and B antigens
  • Group O blood has neither A nor B antigens
Blood Type
In addition to A and B antigens, there is also an Rh antigen. A person's blood type is determined by the presence or absence of the Rh antigen. Individuals who have the antigen are known as Rh positive and individuals without it are known as Rh negative. The combination of an individual's blood group (A, B, AB, O) and the presence or absence of the Rh antigen (+ or -) determine an individual's blood type.

Blood types must be matched between the donor and the recipient to ensure a safe transfusion. The chart below illustrates blood type frequency, red blood cell, and plasma compatibility.

Your Blood Type% of U.S. PopulationYou can receive RED BLOOD CELLS typeYou can receive PLASMA type
O -7%O -AB+, AB-, A+, A-, B+, B-, O+, O-
O+38%O+, O -AB+, AB-, A+, A-, B+, B-, O+, O-
A-6%A-, O-AB+, AB-, A+, A-
A+34%A+, A-, O+, O-AB+, AB-, A+, A-
B-2%B-, O-AB+, AB-,B+,B-
B+9%B+, B-, O+, O-AB+, AB-,B+,B-
AB-1%AB-, A-, B-, O-AB+, AB-
AB+3%AB+, AB-, A+, A-, B+, B-, O+, O-AB+, AB-
  • Type O Negative Donors: Also known as "universal donors," Type O Negative RBCs can be given to anyone. For that reason, Type O Negative blood is often used in emergency situations before a person's exact blood type can be determined.
  • Type O Positive Donors: Approximately 84% of the U.S. population has Rh positive blood. This means that your RBCs can be given to 84% of those in need if their exact blood type is unavailable.
  • Type A Positive/Negative Donors: Your blood type is the second most common U.S. blood type. This means there are many Type A patients out there who need your blood every day. Type A Negative donors can also provide RBCs for the more scarce Type AB patients if necessary.
  • Type B Positive/Negative Donors: As the second rarest U.S. blood type, your blood is needed to keep your elite group of Type B patients safe and healthy. Type B Negative donors can also provide RBCs for the more scarce Type AB patients if necessary.
  • Type AB Positive/Negative Donors: The rarest U.S. blood type at only 4%, Type AB donors are also known as "universal plasma donors", since their plasma can be given to anyone. For that reason, Type AB Positive/Negative plasma is often used in emergency situations before a person's exact blood type can be determined.

The Need for Blood

Since the first volunteer blood donor service opened in 1921, there has been a constant outreach for donors— and here is why:
  1. There is no substitute for human blood.

  2. Every day brings advances in life-saving techniques—many of which require blood or blood products.

  3. Blood products cannot be stored indefinitely.
  • Red blood cells must be used within 35-42 days of collection for the safety of the recipient.
  • Platelets have an even shorter shelf life—they must be used within five days of collection.

Because blood may be needed at any time, it must be collected regularly. No one expects to need blood, however, if it is not available when the need arises, the consequences can be fatal. Although those who donate can tell you there is no better feeling than saving a life, about only five percent of eligible donors actually donate. That is why regular donors—those who commit to giving blood once a season—are so important in ensuring blood is available year-round.

Who needs blood?

Blood and blood products are used for patients of all ages for many reasons—from cancer patients or surgical patients, to those with battlefield injuries, military members depend on blood donors every day. Each unit is critical when you consider:
  • 40 or more units of blood may be needed for a single trauma victim.
  • 8 units of platelets may be required daily by leukemia patients undergoing treatment.
  • A single pint of blood can sustain a premature infant’s life for two weeks.

How much blood is needed?

The ASBP supplies blood and blood products for 1.3 million service members and their families across the nation and around the globe every year. This means blood must be available for routine military medical treatment facility operations as well as contingency operations.

Since the ASBP’s inception more than 60 years ago, more than 1.5 million units of blood have been provided to treat battlefield illnesses and injuries. In addition to providing blood in combat situations for those in critical need, the ASBP also supports the peacetime needs of military personnel and their families. Blood must be available to military hospitals for scheduled and emergency procedures.

What can I do?

Donate blood. This simple act means more than you will ever know to those who need it. The actual donation only takes about 10 minutes and the entire process takes about 45 minutes to one hour. Donors can:
  • Save up to three lives with a single donation!
  • Give blood every 8 weeks or give platelets up to 24 times per year.
  • Help a fellow service member when they need it most.
Deferred from donating? We still need you! There are many ways you can support the mission. Visit our How to Help section to find out how you can save lives by ensuring that blood is available whenever and wherever needed.

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<<May 2021>>
Whole blood donations only.
Platelet donations can be made
up to 24 times per year.