About Bleeding Disorders
Hemophilia is a genetic bleeding disorder that prevents the blood from clotting normally. The primary symptom is uncontrolled, often spontaneous bleeding in different areas of the body. The amount of bleeding depends on the severity of hemophilia. Internal bleeding, which commonly occurs in the spaces around joints, frequently results in pain and swelling. If left untreated, it can cause permanent damage.
Hemophilia results from a missing or deficient protein needed for blood clotting. The two main forms are hemophilia A (factor VIII deficiency) and hemophilia B (factor IX deficiency).
Hemophilia A occurs in 1 in 5,000 live male births. Hemophilia A is about four times as common as hemophilia B. The number of people with hemophilia in the United States is estimated to be about 20,000 individuals.
The worldwide incidence of hemophilia is not well known, but estimated at more than 400,000 people. Approximately 75% of people with hemophilia around the world still receive inadequate treatment or have no access to treatment.
There is currently no cure for hemophilia. There are very effective treatments available in the US, but they may require lifelong infusion of expensive drugs that are manufactured from human plasma or through recombinant biotechnology.
Nearly 90% of Americans with severe hemophilia became infected with AIDS in the 1980s when blood and plasma donations in the US were not properly screened for HIV.
Improvements in donor screening and current viral inactivation measures in the commercial manufacturing process have made clotting factor products are very safe. CDC’s blood safety surveillance system, in place since 1998, has found no reported cases of HIV or hepatitis infections associated with clotting factor products among hemophilia patients.
von Willebrand disease (VWD) is a genetic disorder in which the blood does not clot properly. It is caused by a deficient or defective blood protein, von Willebrand factor. VWD is believed to be the most common bleeding disorder. It is estimated to affect up to 1% of the US population. Of the main subtypes, type I (the mildest form) is most common, accounting for 70% of all cases. Symptoms include frequent nosebleeds, easy bruising and excessive bleeding following surgery or dental work. Although VWD occurs in men and women equally, women are more likely to experience additional complications as a result of heavy or abnormal bleeding during their menstrual periods and excessive bleeding after childbirth.