Hemophilia is a condition in which blood does not clot naturally, and a person with hemophilia could bleed to death if injured. A hemophiliac must receive regular injections of what blood part to stay alive?
Depends on the type of hemophilia they have: people with hemophilia A are deficient in factor VIII (a clotting protein) and use infusions of factor VIII concentrate to control bleeds. People with hemophilia B are deficient in factor IX and use infusions of factor IX concentrate to control bleeds.