Each year, millions of people receive blood transfusions. According to the Mayo Clinic, there are several different ways to donate blood:
- Whole Blood. According to the Mayo Clinic, the most common type of blood donation is a “whole blood” donation. Volunteers give approximately one pint of blood. After the blood is received, it is divided into its separate components -- red cells, plasma, and platelets.
- Platelets. To donate platelets, a process called apheresis is used. According to the Mayo Clinic, apheresis is a process that collects platelets and some plasma from a donor while hooked up to a machine. After the products are collected the rest of the blood is returned to the donor.
- Plasma. Collecting plasma also uses the apheresis process. Plasma may be collected at the same time as a platelet donation or it may be collected solely.
- Double red cells. According to the Mayo Clinic a double red cell donation is also done using apheresis, however only the red cells are collected.
Blood and blood products cannot be created. Clinics are therefore required to rely on volunteers for blood donations. The American Red Cross has both general and specific eligibility guidelines in place, however it is also recommended to check at a local clinic for state guidelines.