Knowing your blood type is important, mainly because it determines who you can donate blood to, but also who you can receive blood from.

There are four basic blood groups: A, B, AB and O. Each is defined by which molecules called antigens and antibodies are present on the surface of red blood cells. Type A blood contains A antigen and the B antibody. Type B contains the B antigen, and the A antibody and Type AB contains both – A and B antigens and no antibodies. Type O contains neither.