Help save lives by donating blood. There is no substitute for human blood. If patients lose blood from surgery or injury or if their bodies can’t produce enough, there is only one place to turn—volunteer blood donors. Each year about 15.7 million units of whole blood and red blood cells are donated in the United States by approximately nine million volunteer blood donors. These units are transfused to about four million patients per year. Blood Centers of the Pacific provides blood for a population of more than 2.2 million. To do this, we need to collect approximately 500 pints of blood daily.