In most cases, O RhD negative blood (O-) can safely be given to anyone. This means you can be 1 of 8 blood groups:Ībout 85% of the UK population is RhD positive (36% of the population has O+, the most common type). If it's absent, your blood group is RhD negative. If this is present, your blood group is RhD positive. Red blood cells sometimes have another antigen, a protein known as the RhD antigen. The NHS Blood and Transplant (NHSBT) website has more information about the different blood groups. This is why group A blood must never be given to someone who has group B blood and vice versa.Īs group O red blood cells do not have any A or B antigens, it can safely be given to any other group. Receiving blood from the wrong ABO group can be life-threatening. For example, if someone with group B blood is given group A blood, their anti-A antibodies will attack the group A cells. Almost half of the UK population (48%) has blood group O. blood group AB – has both A and B antigens, but no antibodiesīlood group O is the most common blood group.blood group O – has no antigens, but both anti-A and anti-B antibodies in the plasma.blood group B – has B antigens with anti-A antibodies in the plasma.blood group A – has A antigens on the red blood cells with anti-B antibodies in the plasma.There are 4 main blood groups defined by the ABO system: They recognise foreign substances, such as germs, and alert your immune system, which destroys them.Īntigens are protein molecules found on the surface of red blood cells.

They're part of your body's natural defences. Your blood group is identified by antibodies and antigens in the blood.Īntibodies are proteins found in plasma. Antibodies and antigensīlood is made up of red blood cells, white blood cells and platelets in a liquid called plasma. Your blood group is determined by the genes you inherit from your parents.Įach group can be either RhD positive or RhD negative, which means in total there are 8 blood groups. There are 4 main blood groups (types of blood) – A, B, AB and O.

What is a negative blood type mean