Blood is separated into types using certain red blood cell characteristics. There are eight blood types; some are rarer than others.
What Is Blood Type
Blood type is determined by the presence or absence of two particular antigens (molecules) on the surface of a person's red blood cells, antigens A and B. If the person's blood only has A antigens, it is type A; if it only has B antigens, it is type B. If the person has both antigens, her blood type is AB. If she has neither, it is O. These types are further classified using another antigen. If it is present, the person is Rh positive; if not, he is Rh negative.
What Determines Blood Type
Blood type is genetic, based on what types of blood your parents had.
The blood types are not all compatible with one another. If incompatible types are used during a transfusion or organ transplant, the patient's body will react against the different type.
B Positive Relatevely Rare
B positive is one of the less common blood types; only 9 percent of people have it. The most rare type is AB negative, which only 1 percent have, and the most common is O positive, occurring in 38 percent of people.
Some believe that people of certain blood types exhibit certain personality traits, somewhat like signs of the zodiac. People with blood type B are considered strong, optimistic, creative, individualistic, flexible and unpredictable.