Blood Facts

General Blood Info

  • Blood makes up about 7% of your body's weight.
  • A newborn baby has about one cup (8 ounces) of blood in his or her body.
  • There are four main blood types: A, B, AB and O. AB is the “universal recipient” and O negative is the “universal donor”.
  • Shortages of all types of blood donations most often occur during summer and winter holidays.
  • Giving blood will not decrease your strength.
  • You cannot get AIDS or any other infectious disease by donating blood.

The Need for Blood

  • More than 4.5 million patients need life-saving blood transfusions each year in the U.S. and Canada
  • 43,000 pints of donated blood are used each day in the U.S. and Canada.
  • Every two seconds, someone needs blood
  • On average, one out of every 7 people entering the hospital will need blood.
  • Blood banks often run short of type O and B blood.
  • The average red-cell transfusion amounts to 2.7 pints.

Reasons People Need Blood

  • Cancer
  • Surgery
  • Heart and blood vessel disease
  • Diseases of the gastrointestinal (GI) tract
  • Emergencies (accidental injuries, burns, etc.)

Blood Components

  • Blood is composed of four main components: Red blood cells, white blood cells, platelets, and plasma.
  • Blood cells are produced in the bone marrow. Vertebrae, ribs, pelvis, skull, and sternum are especially productive cell factories.
  • A pint of donated blood is separated in the lab into components to be transfused individually based on need.

Red Blood Cells

  • Disc-shaped cells that contain iron-rich hemoglobin that delivers oxygen throughout the body.
  • Characteristic red color comes from hemoglobin.
  • Can be stored for 42 days after donation.

White Blood Cells

  • Larger than red blood cells and can leave the blood stream to reach other tissues.
  • Function as part of the immune system by attacking foreign cells and particles. 


  • Small, irregular cells that help control bleeding.
  • Form clusters to plug small holes in blood vessels and help clotting process.
  • Can be stored for only 5 days after donation.


  • A pale yellow mixture of water, proteins, and salts that makes up the liquid portion of the blood.
  • Circulates the other cells as well as nutrients, enzymes, and hormones. 
  • Can be frozen and stored up to a year after donation.