"The Healthy Geezer" answers questions about health and aging in his weekly column.
Question: What is the most common blood type?
Answer: The approximate distribution of blood types in the U.S. population is as follows:
- O-positive: 38 percent
- O-negative: 7 percent
- A-positive: 34 percent
- A-negative: 6 percent
- B-positive: 9 percent
- B-negative: 2 percent
- AB-positive: 3 percent
- AB-negative: 1 percent
It's important to note that the blood type distribution may be different for specific racial and ethnic groups.
Type O-negative blood is called the universal donor type because it is compatible with any blood type. Type AB-positive blood is called the universal recipient type because a person who has it can receive blood of any type.
People over age 69 receive half of all transfusions of whole blood and red blood cells, according to the National Blood Data Resource Center (NBDRC).
With an aging population and advances in medical treatments requiring blood transfusions, the demand for blood is increasing. On any given day, an average of 38,000 units of red blood cells are needed.