Haemophilia is an inherited bleeding disorder where the blood doesn't clot properly. It is caused when blood does not have enough clotting factor. A clotting factor factor is a protein in blood that controls bleeding.

Haemophilia A, or Classical Haemophilia, is the most common form, and is caused by having reduced levels of factor VIII (8). Haemophilia B, or Christmas Disease, is caused by having reduced levels of factor IX (9).

In Australia there are more than 2,800 people diagnosed with haemophilia, who are mostly male. Severe haemophilia in females is very rare, but some females have lower factor levels and bleeding symptoms. Both males and females with less than 40% of the normal level of clotting factor are now recognised as having haemophilia. 

Bleeding is most commonly internal. The low levels of clotting factor produce a wide range of bleeding episodes, usually into the joints or muscles. These bleeding episodes, or “bleeds”, may occur spontaneously, without an obvious cause, or as a result of trauma or injury. Specialised treatment is needed to help blood clot normally and is often infused or injected into a vein. If internal bleeding is not quickly stopped with treatment, it will result in pain and swelling. Over a period of time bleeding into joints and muscles can cause permanent damage such as arthritis, chronic pain and joint damage requiring surgery.

Date last reviewed: March 2018