There are actually 4 blood forms: A, B, AB, or O. Also, blood is possibly Rh-favourable or Rh-destructive. So When you've got style A blood, It can be both A beneficial or maybe a adverse. Which type you're is important if you need a blood transfusion. Plus your Rh https://www.youtube.com/watch?v=buIHtQY7fCU