Bleeding disorders
Bleeding disorders are conditions that affect the way blood clots. When the clotting process does not work properly, bleeding can be prolonged after injury, surgery or even occur spontaneously.
Haemophilia is one of the best-known bleeding disorders, caused by a deficiency in specific clotting factors. Other conditions, such as von Willebrand disease, also impair the clotting mechanism. Some bleeding disorders are inherited, while others can be acquired.
Tests such as the activated partial thromboplastin time (APTT) and prothrombin time (PT) measure how long it takes for blood to clot. These tests help identify which part of the clotting pathway may be affected and guide further investigation.
Symptoms that may prompt testing include unexplained or excessive bruising, prolonged bleeding from cuts, frequent nosebleeds and heavy menstrual periods. If you are undergoing anticoagulant therapy, these tests are also used to monitor treatment.
Causes of Bleeding disorders
Bleeding disorders result from problems with the blood's clotting mechanism. The clotting process involves a complex cascade of proteins (clotting factors), platelets and blood vessel responses working together.
Inherited causes:
- Haemophilia A (factor VIII deficiency) and haemophilia B (factor IX deficiency) are X-linked genetic conditions, meaning they predominantly affect males while females are usually carriers
- Von Willebrand disease is the most common inherited bleeding disorder, affecting both sexes. It involves a deficiency or dysfunction of von Willebrand factor, a protein that helps platelets stick to damaged blood vessel walls
- Rare factor deficiencies (such as factors V, VII, X, XI and XIII) can also impair clotting
Acquired causes:
- Liver disease, since the liver produces most clotting factors
- Anticoagulant medications such as warfarin and heparin, which deliberately reduce clotting ability
- Vitamin K deficiency, as vitamin K is essential for producing several clotting factors
- Disseminated intravascular coagulation (DIC), a serious condition that can develop as a complication of severe illness
Tests that can help check this condition
Learn more on the official NHS page .
