Donating blood.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000740:Anemia / Q000150:complications; D001007:Anxiety; D001771:Blood Banks; D001782:Blood Donors; D001789:Blood Group Antigens; D001794:Blood Pressure; D001803:Blood Transfusion; D001810:Blood Volume; D006400:Hematocrit; D006509:Hepatitis B / Q000150:complications; D006801:Humans; D008288:Malaria / Q000150:complications; D008875:Middle Aged; D010956:Plasmapheresis; D044469:Racial Groups
D001789:Blood Group Antigens
Reprint requests to Baltimore Regional Red Cross, 2701 N Charles St, Baltimore, MD 21218 (Dr. Richmond).