Hemophilia is a bleeding disorder due to inherited deficiencies or abnormalities of coagulation factors. The most common forms, Factor VIII or IX deficiency, are inherited as X-linked recessive traits and essentially occur only in males, though female carriers transmit the abnormal gene. Deficiencies of all other factors are inherited as autosomal recessive traits. Symptoms begin in childhood and persist throughout life. They are similar in type regardless of which factor is deficient, but vary with the severity of the deficiency and are characterized by life threatening hemorrhage from trivial injuries and by bleeding manifestations which are virtually pathognomonic. Large dissecting intramuscular hematomas, hematuria, and epixtaxis are also common. GI bleeding is seen, usually originating from a lesion such as a peptic ulcer. Traumatic or post surgical bleeding may first begin hours or days after injury. Factor XII deficiency is not associated with significant bleeding. If the bleeding site is accessible, pressure, packing with gel foam or fibrin foam, or the use of topical hemostatics such as thrombin may be of temporary value. However, replacement of the missing factor in the form of normal blood or blood products is usually essential. This must be initiated as soon as possible, and should be maintained for two to three days after bleeding has stopped. Therapy must be individualized depending on the diagnosis, the severity and location of the bleeding, and the preparation used.