Group O

Almost half of the donor population have blood group O and it’s the most frequently requested blood group by hospitals. The compatibility and versatility of this group's red cells make it so vital. Whilst group O patients can only receive red cell transfusions of the same group, donations from group O are compatible with all other ABO groups.

O negative is often referred to as ‘universal’ and is arguably the most important blood type. More accurately, it’s the red blood cells that are universal - meaning they can be received by patients of all other ABO groups whether Rh positive or negative. This makes O negative red cells unique in being the only blood type safe to give to a patient whose blood type is unknown or not immediately available, and therefore it is essential in accident and emergency departments.

Around 7-8% of the population have O negative blood, yet demand for this special group accounts for around 13% of all hospital requests. Collecting enough is a constant challenge and we rely heavily on the support and commitment of our existing donors. To ensure we always collect enough we now offer O negative donors ‘priority’ appointments. Priority appointments increase the likelihood that donors will be able to find a suitable time and venue to donate, so that we are able to better manage the high demand for this group.

There’s up to a 1 in 3 chance that if you have O negative blood your blood relatives will share this incredibly important blood group. That’s almost four times more likely than the average person on the street.

O positive is the largest blood type in the donor population and we need to collect a lot. Donations from this group can help treat Rh positive patients of all ABO groups meaning that donors with this blood type can potentially treat an amazing three out of four patients.

Other blood groups