Distribution of blood donor deferrals in the U.S. in 2019 and 2021, by reason
In 2021, there were an estimated two million blood donor deferrals in the United States. The most common reason for donor deferral was low hemoglobin/hematocrit, which accounted for 51.1 percent of all deferrals that year. This graph shows the distribution of blood donor deferrals in the United States in 2019 and 2021, by reason.