Although 60% of US citizens age 16 or older are medically fit to donate blood, only about 5% actually do so. There are some medical conditions that make people ineligible to give blood, such as hepatitis or pregnancy, but there is no upper age limit for blood donors, and individuals can donate blood as often as every 56 days. The need for blood transfusions in the US increases by about 9% each year, and one out of every five hospital patients requires blood. Medical professionals in the US use 32,000 pints (14,195 L) of blood each day in their work with patients.
More about blood donation:
In the US, donors of whole blood are not financially compensated, but some plasma donors receive payment. Many employers do, however, offer time off to workers who want to donate blood.
Donors typically spend about 45 minutes from the time they check into a donation center until the time they leave, but the donation itself takes only about 10 minutes.
The World Health Organization has established 14 June as World Blood Donor Day to draw attention to the need for people to donate blood. That date was chosen because it is the birthday of Karl Landsteiner, who created the ABO blood grouping system.