Hemophilia is a rare disorder in which the blood doesn't clot in the typical way because it doesn't have enough blood-clotting proteins (clotting factors). If you have hemophilia, you might bleed for a longer time after an injury than you would if your blood clotted properly. World Hemophilia Day was started in 1989 by the World Federation of Hemophilia. April 17th was selected as World Hemophilia Day to commemorate the birthday of Frank Schnabel, who founded the World Federation of Hemophilia.