Blood is carried throughout the body in blood vessels. When a vessel gets injured, blood clotting (also called coagulation) is an important part of the healing process. Cells and proteins in the blood work together to form a clot over the injury so that the vessel doesn’t bleed excessively.
When a child has hemophilia, his blood doesn’t clot normally. While he won’t necessarily bleed more than other children, he may bleed for longer. He may also have internal bleeding, where he bleeds inside of his body.
Hemophilia can range from mild to severe. In severe cases, the excessive bleeding can damage his tissues and organs, which can be life-threatening.
About 400 babies are born with hemophilia each year, making it a very rare condition. It is more common in boys than girls.