There are eight different common blood types, which are determined by the presence or absence of certain antigens. Antigens are substances that can trigger an immune response if they are foreign to the body. The four major blood groups are A, B, AB and O. The blood type is either positive or negative if the antigen called the Rh factor is present or absent. The most common blood type is O Positive, and AB Negative is the rarest.
*There will be a blood drive at the West Warwick Public Library on Tuesday, April 3, 2012 from 3 PM to 6PM in the Bloodmobile.