n.
Hereditary bleeding disorder caused by deficiency of a coagulation factor.
Lack of factor VIII causes classic hemophilia; other types are caused by deficiency of factor IX or XI. The first two are transmitted by sex-linked heredity; the third has dominant inheritance and occurs in females as well as males. Spontaneous bleeding may occur. Even trivial injury can cause life-threatening blood loss. Drugs can be given to stop bleeding. Heavy blood loss requires blood transfusions.