Last reviewed: March 2015
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 2,950 people with haemophilia, who are nearly all male. Severe haemophilia in females is very rare, but some have lower factor levels and bleeding symptoms. Any females who have factor levels below 40% may be described as having mild or moderate 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.
Haemophilia is an inherited condition and occurs in families; however, in 1/3 of cases it appears in families with no previous history of the disorder. The genetic alteration causing haemophilia is passed down from parent to child through generations. Men with haemophilia will pass the altered gene on to their daughters but not their sons. Women who carry the altered gene can pass it on to their sons and daughters. Sons with the gene will have haemophilia. Some women and girls who carry the gene may also experience bleeding problems.
The diagrams below may assist in understanding this. The red males are those with haemophilia; the red and blue females carry the gene - they have X chromosome with the genetic alteration and one unaltered X chromosome.
With appropriate treatment haemophilia can be managed effectively.
For more information and frequently asked questions – click here - Haemophilia FAQ.
Download the HFA information booklets about haemophilia:
Haemophilia (2013) - [PDF, 1.7MB]
Click here for other HFA publications on haemophilia.
Australian Bleeding Disorders Registry (ABDR) Annual Report 2012-2013. Canberra: National Blood Authority, 2014.
National Blood Authority; Australian Haemophilia Centre Directors’ Organisation. Evidence-based clinical practice guidelines for the use of recombinant and plasma-derived FVIII and FIX products. [PDF, 1.26MB] Australian Health Ministers’ Advisory Council, Canberra, June 2006.
World Federation of Hemophilia. Guidelines for the management of hemophilia. 2nd edn. Montreal: WFH, 2012.
Important Note: This information was developed by Haemophilia Foundation Australia for education and information purposes only and does not replace advice from a treating health professional. Always see your health care provider for assessment and advice about your individual health before taking action or relying on published information.
This information may be printed or photocopied for educational purposes.