Secondary Hæmorrhage.
Besides the bleeding which may occur immediately on the infliction of a wound, there is another variety which may take place subsequently, known as Secondary Hæmorrhage. This occurs when there is some failure in the process previously described, by which the wound heals. The coagulum is disturbed and the vessels are practically re-opened, or the coagulum becomes softened through the action of an infective agent. As a rule secondary hæmorrhage indicates some form of infection.
Often in changing the dressing there is a minute amount of hæmorrhage. This is due to injuring the developing blood vessels in the newly growing scar tissue.