Although it is easy to identify the blood type of a person with the help of lab tests, it will really be helpful and save a lot of time in case the person knows his blood group.
The Bombay blood group (hh), a relatively unknown blood type, is also one of the most uncommon blood types in the world.
But only certain metrics stood out — for example, the people with type A blood tended to have higher levels of total cholesterol and LDL cholesterol, also known as the "bad" cholesterol.
It's possible that higher cholesterol levels could partly explain the increased mortality risk.
The second most uncommon blood type is B- (B negative).
It is found in 1.5-2% of the total world population, i.e., two in 70-100 people.