What does negative and positive mean regarding blood types?

1. 60

   Roger Rabbitposted 14 years ago

   What does negative and positive mean regarding blood types?

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2. 60

   whizzerposted 14 years ago

   I'm sure you've heard of the A,B,O blood groups, where a person is either group A, B, AB or O. Well, the positive or negaitive refers to the Rhesus factor, which another type of blood group.
   
   A person is grouped according to their A, B, AB or O status and then they are also grouped according to whether they have the Rhesus antibody or not. If they do, they are positive, if not they are negative.
   
   So, if somebody is A+ they have blood group A and they also have the Rhesus antibody. If they are A- then they are blood group A but they do not have the Rhesus antibody.
   
   There are other blood antibodies apart from the ABO system and the Rhesus system but they are rarer and not often mentioned. They do exist however. That is why if somebody needs a blood transfusion they are fully cross-matched to ensure total compatibility.

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3. 93

   Jlbowdenposted 14 years ago

   Hello Roger Rabbit:
   
      This could end up sounding more difficult to you than it really is, but basically there are three blood types. A,B, AB and O. These blood types are given the term antigens. Also we inherit these antigens from our parents. The + Or - of this equation is call RH, also sometimes called a big D antigen. The RH is also inherited. So in summary the Antigens and RH have a lot to do with the negative and positive of the equation, when you see blood types...AB- O+ (which is the most common blood type). Hope this made some sense?
   
   Jl

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4. 60

   craftybegoniaposted 14 years ago

   To people, it sometimes means trouble. My aunt had a negative blood type and she was in need of blood and it was pretty hard to find a healthy donor with her type! I also knew a couple, he was positive and she was negative and they had some concerns about having a healthy baby (and he knew, because he is a doctor.) So, it could mean trouble for a person under certain circumstances. If you are healthy, it's no problem.

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5. 60

   fucsiaposted 14 years ago

   The positivity means that in red blood cells there is a specific factor that in the negative people there is not. The negative person may receive blood only from negative people, while those who are positive can receive blood from both types.

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6. 71

   akanga1posted 14 years ago

   whizzer's answer really sums it up nicely. It is to do with the 'Rhesus' groups. You either have the rhesus antigens (protein) in which case you are 'Positive' or you don't, in which case you are 'Negative'. If you want to explore the issue of these and the other, lesser known, blood groupings, there are good details on http://www.pregnancy-bliss.co.uk/anti-D.html

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