I signed up to donate blood at work tomorrow, but I don't know if I am going to donate whole blood or just red cells.

When you donate just red cells they spin those cells out and pump your plasma along with some saline solution back into your body. They can take twice as many red cells this way than when you donate whole blood, so it is like donating two pints instead of just one.

The only thing is it kind of freaks me out that they are pumping stuff back into me. I am OK with sterile bags of IV drugs, but it just seems like it would be easy to contaminate my blood while it is outside of my body during the separation process. The rational side of me says it is completely safe and they wouldn't do it if it wasn't, but it just freaks me out.

On the other hand I think the humanitarian side of me wants to do as much good as possible, so I think I will probably get over it and donate just red cells. It takes longer, but they said it is more comfortable because they use a smaller needle.