Coagulation (Bleeding) Disorders

How blood clotting works

Stopping bleeding (hemostasis) happens in stages:

1. Blood vessels narrow at the injury.
2. Platelets stick to the damaged vessel wall, helped by von Willebrand factor, and clump to form a plug.
3. Clotting factors (proteins numbered I to XIII) activate in a cascade to form fibrin, a mesh that strengthens the plug.
4. The clot is later dissolved as the vessel heals.

A problem at any step can cause a bleeding disorder.

Types of coagulation disorders

Inherited

Acquired

• Blood thinners: warfarin, direct oral anticoagulants, heparin and antiplatelet drugs
• Liver disease: the liver makes most clotting factors
• Vitamin K deficiency: in newborns, malnutrition, malabsorption or long antibiotic use
• Thrombocytopenia: low platelet count from many causes
• Disseminated intravascular coagulation (DIC): widespread clotting and bleeding in severe infection, trauma, cancer or pregnancy complications
• Acquired hemophilia: autoantibodies against factor VIII, mainly in older adults or after childbirth
• Kidney failure: impairs platelet function
• Massive blood loss and transfusion

Symptoms

Bleeding patterns hint at the type:

• Platelet and von Willebrand problems: bruising, nosebleeds, bleeding gums, heavy periods, tiny red skin spots, bleeding after dental work
• Clotting factor problems (such as hemophilia): deep bleeding into joints and muscles, large bruises, delayed bleeding hours after surgery or injury
• Both: prolonged bleeding from cuts, bleeding after childbirth, blood in urine or stool

Bleeding disorders in women

Women with bleeding disorders are often undiagnosed because heavy periods are thought to be normal. Signs include periods lasting more than 7 days, flooding or clots larger than a quarter, needing to change protection every hour, iron deficiency anemia, and heavy bleeding after childbirth. The CDC encourages women with these signs to ask about testing.

Diagnosis

A doctor will take a bleeding history (sometimes using a standardized bleeding score), ask about family history and medicines, and examine for bruises and joint swelling. Tests include:

• Complete blood count: platelet count and anemia
• Prothrombin time (PT/INR): tests factors VII, X, V, II and fibrinogen. Prolonged in warfarin use, vitamin K deficiency and liver disease
• Activated partial thromboplastin time (aPTT): tests factors XII, XI, IX and VIII. Prolonged in hemophilia and some von Willebrand disease
• Fibrinogen level
• Von Willebrand panel: antigen, activity and factor VIII
• Specific factor assays
• Platelet function tests
• Mixing studies to detect inhibitors
• Genetic testing for inherited disorders

Normal basic tests do not rule out von Willebrand disease or platelet problems, so specific tests are needed when the history suggests a bleeding disorder.

Treatment

Treatment depends on the type and severity:

• Factor replacement: concentrates of factor VIII or IX for hemophilia, von Willebrand factor concentrates, and others as needed. Some people use them regularly (prophylaxis) to prevent bleeds.
• Non-factor therapies: emicizumab, a weekly to monthly injection that prevents bleeding in hemophilia A, and newer gene therapies for some people with hemophilia.
• Desmopressin (DDAVP): releases stored von Willebrand factor and factor VIII, useful in mild hemophilia A and many types of von Willebrand disease.
• Antifibrinolytics: tranexamic acid or aminocaproic acid stabilize clots, especially for mouth bleeding, nosebleeds and heavy periods.
• Vitamin K: for deficiency or warfarin reversal.
• Platelet transfusions, fresh frozen plasma or cryoprecipitate in some situations.
• Hormonal treatment for heavy periods.
• Treating the cause of acquired disorders, such as infection in DIC.

Living with a bleeding disorder

• Register with a hemophilia treatment center if you have an inherited disorder
• Tell every doctor and dentist before procedures
• Avoid aspirin and NSAIDs unless advised; use acetaminophen (paracetamol) for pain
• Wear a medical alert bracelet
• Choose low-contact activities such as swimming and cycling if bleeding is severe
• Plan pregnancy and delivery with specialists

Frequently asked questions

What is a coagulation disorder?

It is a condition in which blood does not clot properly, leading to easy bruising, prolonged or heavy bleeding. It can be inherited, such as hemophilia or von Willebrand disease, or acquired from liver disease, vitamin K deficiency, medicines or serious illness.

What is the most common bleeding disorder?

Von Willebrand disease is the most common inherited bleeding disorder, affecting up to 1 in 100 people, although many have mild symptoms and are never diagnosed. Hemophilia is much rarer and mainly affects males.

What are the signs of a bleeding disorder?

Common signs are easy or large bruises, frequent or long nosebleeds, bleeding gums, heavy or long periods, prolonged bleeding from cuts, and excessive bleeding after dental work, surgery or childbirth. Bleeding into joints is typical of hemophilia.

How are bleeding disorders diagnosed?

Diagnosis starts with a bleeding history and basic blood tests: blood count, PT/INR, aPTT and fibrinogen. Specific tests for von Willebrand factor, individual clotting factors and platelet function are often needed, because basic tests can be normal.

Can bleeding disorders be cured?

Most inherited bleeding disorders are lifelong but well controlled with treatment. Gene therapy now offers long-term factor production for some people with hemophilia. Acquired bleeding disorders often resolve when the cause, such as vitamin K deficiency or a medicine, is treated.