Bleeding disorders are a group of conditions in which there is a problem with blood clotting. These disorders can lead to undue spontaneous bleeding, or to heavy and prolonged bleeding after injury or with menstruation.
Normal blood clotting involves as many as 20 different plasma proteins, which are known as blood clotting or coagulation factors. Blood clotting also requires blood platelets that are sufficient in number and have no functional deficits. These coagulation factors act together with platelets and other molecules to form a platelet plug that stops bleeding. Problems can occur when platelets, or certain coagulation factors are low, missing or dysfunctional.
Causes and Symptoms
Some bleeding disorders are inherited — present at birth and are passed through families. Others are acquired by Vitamin K deficiency, severe liver disease, bone marrow disorders, or use of drugs to stop or prevent thromboembolism (anticoagulants such as Coumadin, or anti-platelet drugs such as aspirin).
Symptoms can be bleeding into joints and muscles, excessive bruising, heavy and prolonged bleeding after injury (such as a cut), heavy menstrual bleeding, excessive nosebleeds, prolonged bleeding after circumcision and dental procedures, as well as heavy gum bleeding.
While bleeding disorders are rare, these are among the most frequent:
- Hemophilia (factor VIII or factor IX deficiency) - approximately 1 in 5,000 males
- Von Willebrand disease (vWD) - up to 1%-2% of the population may have some form
- Idiopathic thrombocytopenic purpura (ITP) - approximately 1 in 15,000 adults
There are many more inherited bleeding disorders, comprising factor deficiencies or platelet disorders, such as Glanzman thrombasthenia or Bernard Soulier-syndrome, that are truly rare (1 in 500,000 or 1 in 1 million people) or are only present in certain families. The rarest bleeding disorder may be factor XIII deficiency, with 1 in 5 million people affected.
The American Society of Hematology (ASH) has published comprehensive patient information for people affected by bleeding disorders.