Rare blood group: The rarest blood type

The rarest blood type is called Rhnull . Only around 1 in every 6 million people have Rhnull blood. Learn about other blood types and their compatibilities in this article. There are eight blood types, divided into four categories: A, B, AB, and O, and whether Rh positive or negative. These types are determined by antigens on red blood cells. Learn what this means. Learn about rare blood groups in India explained with types, prevalence, and their importance in medical emergencies and blood donation. Check the blood types graph and know the most common & rare blood groups in India with updated percentage data. Easy chart explained for 2025.