The general term haemophilia describes a group of inherited blood disorders in which there is a lifelong defect in the clotting mechanism of the blood. Blood contains many proteins called clotting factors, and these work to stop bleeding. The lack of clotting factor causes people with haemophilia to bleed for longer periods of time than people whose blood factor levels are normal. However, people with haemophilia do not bleed faster than other people. Most bleeding in haemophilia occurs internally, into the joints or muscles. The joints that are most often affected are the knee, ankle and elbow. Repeated bleeding without prompt treatment can damage a joint. The incidence of haemophilia in the general population is 1 in 10,000 (therefore about 1 in 5,000 of the male population has haemophilia).
There are two types of haemophilia. Haemophilia A which is a deficiency in factor VIII and haemophilia B (or Christmas Disease) is a deficiency in factor IX. Both types of haemophilia share the same symptoms and inheritance pattern, only blood tests can differentiate which factor is affected. The severity of the condition is related to the degree of deficiency of the relevant clotting factor in the blood.
Haemophilia is a genetic blood disorder, which is usually inherited. The gene is passed down from a parent to a child. A person who is born with haemophilia will have it for life. Some of the signs of haemophilia are large bruises, bleeding into muscles and joints, spontaneous bleeding, and bleeding for a long time after a cut or surgery.