- Classic Hemophilia or Hemophilia A: Hemophilia A is caused by the absence of the 8th antihemophilic factor in blood clotting. 80% of affected patients have hemophilia A.
- Christmas Haemophilia or Haemophilia B: Haemophilia B is caused by the absence of Christmas, the 9th clotting factor. 20% of affected patients have hemophilia B.