what is haemophilia

Haemophilia

Haemophilia describes a group of inherited blood disorders in which there is a life-long 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.

Figure 1: The normal clotting
Figure 2: The clotting process in a person with haemophilia, where a clotting factor is missing.

There is a common misconception that people with haemophilia bleed a lot from minor cuts. In reality, external cuts, wounds, or bruises are usually not serious. 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 result in long term damage to the joint or muscle. When bleeding occurs in a vital organ, especially the brain, this can be very serious.

Haemophilia is a genetic blood disorder, which is usually inherited. The gene is passed down from a parent to a child (see more). A person who is born with haemophilia will have it for life. Some of the signs of haemophilia are: large or frequent bruising, bleeding into muscles and joints, spontaneous bleeding and bleeding for a long time after a cut or surgery. In women, menstrual bleeding can also be a significant symptom.

There are two types of haemophilia:

Haemophilia A which is a deficiency in factor VIII. The incidence of haemophilia in the general population is 1 in 10,000 or 1:5000 males

Haemophilia B (sometimes called Christmas Disease) is a deficiency in factor IX. This is a less common form and has an incidence of haemophilia in the general population is 1 in 50,000 or 1: 25,000 males