Knowing your blood type is critical during emergency health situations. Blood type is a personal medical detail that doesn't come up much in casual conversation or even at doctor's visits, so I ...

But what determines blood type and what does that blood type mean? Blood types are determined by antigens -- a substance that triggers an immune response -- on the surface of red blood cells.

If you don't know your blood type, you're not alone. However it is important medical information to know, and here's how you can find it.

It can affect everything from your risk for certain conditions to how your body handles a blood transfusion. If you're not sure of your blood type, there are a few easy ways to find out.