Transfusions are procedures where blood or blood products are pumped into your bloodstream. They can help replace blood lost during accidents or operations; boost red cell count in anemic patients; supply clotting factor for hemophiliacs, so their blood will thicken when needed; and increase white blood cells in those receiving chemotherapy. Donated blood is known as 'whole blood,' which is broken down into a number of ingredients, including platelets, liquid plasma, clotting factor, and red blood cells. So blood may be properly matched to patients, it is separated according to one of three types: A, B, or O and labeled either positive or negative. Scientists then look for antibodies that might set off an allergic response. Finally, the blood products are rigorously tested for H-I-V, hepatitis, syphilis, and human T-lymphotropic (Tee lim-foe-TROE-pic) virus. This screening process makes it highly unlikely that you would contract H-I-V or another infectious disease through a single blood transfusion. That doesn't mean transfusion is completely without risk, but it's still much safer than not getting blood when it's medically necessary. There are alternatives to standard transfusion: prior to elective surgery, you could self-donate blood over several visits. Or, medications may be used to lower the amount of blood you need during an operation, or help you avoid a transfusion altogether. For more information, consult a doctor.