What Is Hemophilia?


Hemophilia is an inherited bleeding disorder. Over 50 substances are needed for blood to clot. If one of the clotting proteins is missing, or if the amount of the protein is too low, the person may bleed spontaneously or bleed excessively when trauma occurs.

There are different types of hemophilia, depending on which factor is missing or too low. The two most common forms are hemophilia A or classic hemophilia caused by a deficiency in Factor VIII, which are most common, affecting 90% of patients. Hemophilia B or Christmas disease is caused by a deficiency in Factor IX which affect 9% of patients. Problems also occur with factors XI, X, VII and V but these cases are rare. All of the rare cases combined account for only 1% of patients with hemophilia.

Hemophilia can be mild, moderate, or severe, depending on how much clotting factor is in your blood. About 7 out of 10 people who have hemophilia A have the severe form of the disorder.

People who don’t have hemophilia have a factor VIII activity of 100 percent. People who have severe hemophilia A have a factor VIII activity of less than 1 percent.

Hemophilia usually occurs in males (with rare exceptions). About 1 in 5,000 males are born with hemophilia each year.

What Is von Willebrand Disease?

von Willebrand disease, or vWD, is an inherited disorder that affects the blood’s ability to clot properly. It takes its name from Dr. Erik von Willebrand, who first described the condition in 1926.

von Willebrand disease is the most common inherited bleeding disorder, affecting about 1% to 2% of people. Unlike hemophilia, which usually affects only males, vWD affects both males and females. Symptoms range from mild bruising to potentially life-threatening bleeding. The majority of people with VWD have a mild form.

All forms and severities of hemophilia can be treated. Proper treatment reduces the risk of serious complications and allows patients to lead a full and productive life.