Haemostasis

What is haemostasis?
Haemostasis is the human body's response to blood vessel injury and bleeding. It involves a series of interactions between platelets and numerous blood clotting proteins (or factors), resulting in the formation of a blood clot.

Tissue factor is a protein that comes into contact with blood once a blood vessel is injured. The process of haemostasis starts when tissue factor binds to a coagulation protein called activated factor seven (FVIIa). The binding of tissue factor and FVIIa is only the first step in a process that will eventually lead to the development of a strong, stable blood clot that will stop and prevent further bleeding.

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 minimize blood loss and related injury.

However, some people are born with a bleeding disorder (congenital) that impairs their ability to achieve haemostasis. Most of these bleeding disorders are hereditary, or run in families. An example of this is congenital haemophilia.

In addition, some people who have never had any bleeding problems can develop a condition that causes them to bleed, known as acquired haemophilia. In this disorder, even minor cuts and bruises can require medical intervention.
Haemophilia imposes a heavy medical and economic burden on individual patients and society in general.