Haemostasis is the human body's response to blood vessel injury and bleeding. It involves a series of interactions between cells in the blood called platelets and numerous blood clotting proteins (or factors), resulting in the formation of a blood clot.
Generally, in healthy people control of bleeding is achieved very
quickly and without the need for medical intervention. In major trauma
or surgery, physicians often need to help patients to achieve adequate
haemostasis - in order to minimise blood loss and related
Haemophilia is an inherited (congenital) bleeding disorder that occurs frequently in males. It occurs when the levels of certain clotting factors (factors VIII or IX) are reduced, or are completely absent. This is because the gene that controls the production of the clotting factor does not work properly. In the case of haemophilia A, there is a problem with factor VIII and in haemophilia B it is factor IX. These clotting factors are essential in order to prevent uncontrolled bleeding.
Without these clotting factors, bleeding will continue until
treatment is given because the body is not able to produce sufficient
natural clotting factors to form a clot to stop it.
The normal treatment for haemophilia is to replace the missing clotting factor. However, some people's immune systems respond to these replacement factors by developing antibodies known as inhibitors that prevent the clotting factor from working.