Severity of symptoms can vary, but severe forms become apparent early on. Prolonged bleeding is the disease's hallmark and typically manifests itself when an infant is circumcised. Additional bleeding manifestations make their appearance when the infant becomes mobile. Mild cases may go unnoticed until later in life, when they occur in response to surgery or trauma. Internal bleeding may occur anywhere and bleeding into joints is common.
Risk factors are a family history of bleeding and being male.
The incidence of hemophilia B is 1 out of 34,500 men. Prolonged bleeding following circumcision People whose clotting activity is 5 percent of normal may have only mild hemophilia. They rarely have unprovoked bleeding episodes, but surgery or injury may cause uncontrolled bleeding, which can be fatal. Milder hemophilia may not be diagnosed at all, although some people whose clotting activity is 10 to 25 percent of normal may bleed excessively after surgery, dental extractions, or a major injury. Generally, the first bleeding episode occurs before 18 months of age, often after a minor injury.