#WorldHaemophiliaDay: The Basics You Ought To Know

World over, April 17, is celebrated as World Hemophilia Day, by Hemophilia Organizations to increase awareness of Hemophilia. Haemophilia is a genetic disorder. Usually, the males are the active sufferers, the females being carriers. In the recent past, it has been found that haemophilia can also occur in families without a known history.

Causes of Haemophilia:

Haemophilia is caused by the inactivity or deficiency of the clotting factor known as Factor VIII or Factor IX of the blood of the affected patient. The normal level of clotting factor varies between 50% and 150% whereas in persons with haemophilia (PWH’s) it is as low as less than 1%.

The severity of the deficiency gets classified as mild, moderate or severe, based on the factor level. About 25% of the PWHs suffer from a deficiency in Factor IX known as Christmas Disease while the rest suffer from the deficiency of Factor VIII known as Classical Hemophilia.

It is presently estimated that 1 out of 5,000 males is a born a haemophiliac.  Since haemophilia is a sex-linked inheritance, when a man with haemophilia A or B has children, none of his sons will have haemophilia. However, all his daughters will be “carrier”.

A carrier is a term used to describe someone who can hand on haemophilia condition without suffering from it herself. A carrier of Hemophilia A or B can have children that are having the defective gene. The sons will have a 50% chance of having haemophilia and daughters will have a 50% chance being a carrier.

The rare chance of a daughter being a PWH occurs when the mother is a carrier and the father is a PWH.

How blood clots:

Blood travels inside the body through blood vessels which can be thought of as pipes and tubes carrying blood throughout the body. When one of these pipes, i.e. blood vessels gets damaged, blood spills out…In order to stop this leakage, the body does some repair work which is described as follows:

(1) The blood vessel gets smaller so that less blood passes through it.

(2) A platelet plug is formed as a temporary patch over the leak (Platelets are part of our blood cells).The platelets begin sticking to the torn wall of the blood vessel and then to each other to form the plug. This not very strong. It can last for only a few hours. For little scratches and cuts, this is long enough for healing to start but not for bigger injuries.

(3) For bigger injuries, a fibrin clot is formed. This forms a good, strong patch enough to stop the bleed completely. Proteins in the blood, called clotting factors, work together to make the fibrin clot. These clotting factors cause threads of a protein called fibrin to weave over the platelet plug. The fibrin threads make a strong clot. The body has now time to heal the blood vessels. When it is no longer needed, the body gets rid of the fibrin clot.

How blood clots for a Person With Hemophilia (PWH):

(1) The first 2 steps to stop bleeding usually work fine for a person with haemophilia too.

(2) In cases where fibrin clot is needed, PWH’s do not have enough of certain clotting factors. Because of this, the fibrin clot is not made or it is so thin that the bleeding goes on. Thus PWH’s do not bleed faster than a normalperson but they bleed longer.


There are several types of Hemophilia based on which clotting factor is deficient. They are:

  • Deficiency of Factor VIII is called Hemophilia-A
  • Deficiency of Factor IX is called Hemophilia-B
  • Deficiency of Factor XI is called Hemophilia-C


Haemophilia varies in severity and this variability is related to the degree of deficiency of the clotting factor in

the blood. All affected males in a particular family tend to have the same amount of clotting factor.

Severe haemophilia: This means little or no factor (less than 1%) works in the blood. People with severe haemophilia tend to bleed often, sometimes once or twice a week, even with no known injury (spontaneous haemorrhage).

Moderate haemophilia: This means some factor works (between 2-5%) in the blood. Bleeding occurs usually only

after some injury, and maybe only once a month on average. Spontaneous haemorrhage is uncommon.

Mild haemophilia: This means a lot of factors (6% and above) work in the blood. Bleeding sometimes doesn’t happen even after an injury. Bleeding occurs maybe only a few times a year. But teens with mild hemophilia will need to have an infusion of factor if they have their teeth pulled or have surgery. Diagnosis may not be made until adulthood when unexplained excessive bleeding may follow major injuries, surgeries or tooth extractions. Anyone having a bleeding disorder or doubts about

Anyone having a bleeding disorder or doubts about Haemophilia can contact Hemophilia Society – Madras Chapter at the Voluntary Health Services Hospital (VHS), Tharamani, Chennai – 600 113. Phone No. 22541652.