One of the most important things in human biology and one that is relevant to all human beings is blood. Blood is divided into types, and although these blood types are not so much an issue in diagnosis of illness by blood test, the importance of being aware of blood types is.
Blood aids the immune system and the red and white cell balance is important to sustain good health. Knowing the types of blood in which an individual falls can mean that hospitals and emergency services can replace blood in a situation of extreme need. During many illnesses blood can be lost, and these include things as simple as pregnancy and everyday illnesses that people don't see as life threatening, although the risk factor is decreased by having a note of your blood type.
TYPES and GROUPS
Blood types are split into groups. The group entitled ABO is the more common, and here the importance is that only certain types can be used as replacements and knowing the exact type is essential.
A Group Blood for example can only be replaced with blood of a similar type.
B Group similarly can only be replaced by other B group blood
AB is more flexible and can be replaced by either A or B, making it easier to match.
O Type blood can be used in a mixture of blood for donation purposes, and is the most valuable in blood donation. Hospitals need more of the O type because of it's valuable flexibility of use with other bloods, and giving O type blood is essential to keep blood banks available for the health needs of hospitals. O types themselves can only be transfused with O type.
Being aware of how careful the screening of blood is in different parts of the world is important, since the prevention of diseases such as AIDS has been recognized in many countries, while in others the risk of infection from transfusion is still very real.
Blood is the water of life, and being aware of type can and does save lives. If you consider that in emergency situations, there may not be time for tests and extensive research and that every minute matters, wearing a bracelet that marks your blood type, or one of the tags that can be attached easily to a chain may just make the difference between life or losing it.