Knowing your blood type is important for a lot of reasons. The most obvious one is that if you’re ever hurt and need supplemental blood, getting the wrong type could be life-threatening. Blood type also correlates with other health conditions, though researchers are still studying the connections. Blood type A may be more likely to develop memory and cognition problems and have a higher risk of developing type 2 diabetes. Type B may be at higher risk of heart disease, but lower risk of kidney stones. And type O may be more likely to suffer from fertility issues. Learn more about blood types.