HoG Handbook
 

How Blood Works in a Person With Hemophilia

 

Fibrin ClotAs explained in Understanding How Blood Works, bleeding is supposed to stop after three things happen:

  1. The injured blood vessel gets smaller to let less blood through.
  2. Platelets rush to the site and stick together to form a platelet plug.  The platelets do this through adhesion, activation and secretion, and aggregation.
  3. Clotting factor proteins in the blood work together to make threads of fibrin.  The fibrin weaves itself into a clot over the platelet plug.  This makes a strong seal.

People with Hemophilia Can't Make a Fibrin Clot

The first two steps to stop bleeding usually work just fine in a person with hemophilia.  The blood vessel gets smaller and the platelets make a plug.

Some people think a person with hemophilia can bleed to death from a small cut.  This is not true.  The first two steps are usually able to stop bleeding from cuts and scrapes.

A person with hemophilia has problems when a fibrin clot is needed to stop the bleeding.  People with hemophilia don't have enough of certain clotting factors.  Because of this, the fibrin clot is not made or is so thin that the bleeding goes on. 

Someone with hemophilia does not bleed faster than someone without hemophilia.  However, the person with hemophilia will bleed longer.

Bleeding Inside the Body is the Big Problem

Bleeding inside the body is more of a problem for people with hemophilia than bleeding on the outside from a cut or scrape.  Inside the body, the blood can go into spaces in joints, muscles, and organs.  This can cause great damage, especially if the bleeding is not treated or happens over and over.

Many times the bleeding, especially bleeding in muscles and joints, is caused by an injury.  The person with hemophilia might bump his knee or hit his elbow.  However, for some people with hemophilia, the bleeding can start for no clear reason.  For example, the person with hemophilia could just be walking and have a bleeding start in his knee.  This is called a "spontaneous bleed."  Whether caused by an injury or spontaneous, bleeding must be treated as soon as possible.

People with hemophilia usually don't say they are bleeding.  They say they are having "a bleed."  You will hear them say, "I had four bleeds last month," or "It feels like I'm having a bleed in my ankle."