That is why it is so important for people to donate blood on a regular basis. Dr. Cook recommends that everyone donate blood at least once a year to help maintain the blood supply. It's virtually painless. It only takes a few minutes. And, it will save someone's life, he said.
Blood is divided into types for the purposes of matching blood from the donor to the recipient.
But some types are more common than others. The most common type is O positive. The least common would be AB negative. A lot of people think of the O blood group as kind of being a universal donor. That's not absolutely true.