The open wound will be infected
When your injured , your blood  normally begins to clot(changes the blood form from liquid to solid)   to prevent the massive loss of blood in our bodies....  

if a person's blood does not clot fast enough...  it means that person may have a bleeding disorder... which can cause bleeding inside and  outside of one's body .........
so obviously if you lose so much of your blood you will die...... and if the blood bleeds inside your body... your tissues and other vital organs specially the brain might die in too much blood loss, for as all we know (the blood carry the oxygen and other nutrients all through our body)....

in other words one will die in no time if the body fails to clot blood