Blood Types

We all have these little marker things called antigens on the surface of our red blood cells. These are so tiny they can't even be seen under a microscope. Everyone's got different ones, in fact, only identical twins will ever possess all the same antigens.

Blood groups, Part 1: The ABO system

• If you have blood group A, you've got A antigens covering your red cells.



• Blood group B means you have B antigens.



• Group O has neither.



• Group AB hs a bit of both.

The ABO system also contains lots of little antibodies in the plasma, antibodies being the body's natural defence against antigens. These are pretty much the opposite of other groups. So...

• Group A has anti-B antigens



• Group B has anti-A



• Group O has both



• Group AB has none

Giving someone blood from the wrong blood group (eg, a Group A person been given blood from Group B) could be fatel.

Blood groups, Part 2: The RH system

It gets a bit more complicated when we bring in the RH antigen. Som people have it, some people don't.

If it is present, the blood is positive, if not, it is negetive. For example, someone from Group A will have it, and will therefore be classed as A+ (or A positive). While the ones that don't, are A- (A negative). It's the same for groups B, O and AB.

This doubles the number of different blood types to be matched, because you shouldn't mix blood type A+ with blood type A-.

The Top Ten uses of blood are:

1. General surgery (23%)

2. General Medical (15%)

3. Cardiothoracic - heart and chest surgery (13%)

4. Orthopaedics - bones and bone diseases (11%)

5. Haematology - blood diseases (9%)

6. Accident and Emergency (8%)

7. Renal - kidneys - and Neonatel and Paediatrics - treatment of newborns and children (6%)

8. Intensive care (4%)

9. Obstetrics and Gynaecology - pregnancy and childbirth (3.5%)

Sources: http://www.blood.co.uk/, http://www.foothill.net/(image)