All you wanted to know about blood donors but were too busy to ask.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001771:Blood Banks; D001782:Blood Donors; D005260:Female; D006801:Humans; D007883:Legislation, Medical; D008297:Male; D008875:Middle Aged; D009042:Motivation; D014481:United States