What percent of population has O negative blood type?
It’s not so much that it’s rare (it’s only moderately uncommon in western countries) it’s that the demand for it is higher because it’s especially useful. Red blood cells from O- blood can be transfused into people with any of the 8 main types without a negative reaction. Whilst doctors always match the blood type transfused to the person’s own if possible, they have to test for it. If someone is rushed into a hospital dying from a stab wound, several units of O- will be called for because there’s no time to spend on a test. As O- red blood cells are also the only kind O- types can receive safely, hospital stocks are always lower for O- than any other type. See here, for example http://blood.co.uk/StockGraph/stocklevel… (the days stock, not the units – little AB is in stock, but little is needed) Anyway, to answer your question:
