Bleeding Disorder: Signs, Symptoms and Testing

How clotting normally works

When a blood vessel is injured, two systems work together:

1. Platelets stick to the damaged vessel wall and to each other, forming a plug. Von Willebrand factor (VWF) acts as glue between platelets and the vessel wall.
2. Clotting factors (proteins numbered I to XIII) activate in a chain reaction that forms fibrin, strengthening the plug into a stable clot.

A bleeding disorder results from too few platelets, platelets that do not work properly, or missing or faulty clotting factors.

Signs of a bleeding disorder

The pattern of bleeding offers clues:

Common warning signs:

• bruises larger than a coin from minor knocks, or bruises without remembering an injury
• nosebleeds lasting longer than 10 minutes, or needing medical treatment
• bleeding from cuts that continues more than 5 to 10 minutes
• heavy or prolonged periods since the first period
• bleeding after dental extractions, tonsillectomy or surgery that needs extra treatment
• heavy bleeding after childbirth
• iron deficiency anemia without an obvious cause
• blood in the urine or stools

Bleeding disorders in women

Women with bleeding disorders often go undiagnosed because heavy periods are seen as normal. A bleeding disorder is more likely if you have:

• periods lasting more than 7 days
• flooding through a pad or tampon every 1 to 2 hours
• clots larger than about 2.5 cm (1 inch)
• iron deficiency or anemia
• heavy bleeding since your very first periods

Up to 1 in 5 women with heavy menstrual bleeding have an underlying bleeding disorder, most often von Willebrand disease. Bleeding disorders also increase the risk of bleeding during miscarriage, childbirth and surgery.

Causes

Inherited

• Von Willebrand disease: low or faulty VWF; usually mild, affects both sexes.
• Hemophilia A and B: low factor VIII or IX; X-linked, so mostly affects males, though female carriers can bleed.
• Platelet function disorders: platelets are normal in number but do not work properly. See platelet function disorders.
• Rare factor deficiencies: factors I, II, V, VII, X, XI and XIII.

Acquired

• Medicines: anticoagulants (warfarin, apixaban, rivaroxaban, dabigatran), antiplatelets (aspirin, clopidogrel), NSAIDs, some antidepressants and supplements such as fish oil and ginkgo.
• Low platelets (thrombocytopenia): immune thrombocytopenia, leukemia, chemotherapy, viral infections.
• Liver disease: the liver makes most clotting factors.
• Vitamin K deficiency: from malabsorption, antibiotics or poor diet; newborns without a vitamin K injection.
• Disseminated intravascular coagulation (DIC) in severe illness.
• Acquired hemophilia or acquired von Willebrand syndrome: rare autoimmune or disease-related forms.

See coagulopathy for acquired clotting problems and types of bleeding disorders for a full comparison.

How bleeding disorders are diagnosed

1. Bleeding history: doctors often use a structured bleeding assessment questionnaire.
2. First-line blood tests: - complete blood count (platelet number and anemia) - prothrombin time (PT/INR) and activated partial thromboplastin time (aPTT) - fibrinogen - ferritin for iron stores
3. Specialist tests by a hematologist: - von Willebrand factor antigen, activity and factor VIII - individual clotting factor levels - platelet function tests - genetic testing

Normal first-line tests do not rule out von Willebrand disease or platelet disorders, so specialist testing is needed if the history is suggestive. Test results can be affected by stress, pregnancy, the pill and blood type, so tests are sometimes repeated.

Treatment and management

Treatment depends on the disorder and its severity:

• Desmopressin (DDAVP): releases stored VWF and factor VIII; used for mild von Willebrand disease and mild hemophilia A.
• Tranexamic acid: prevents clots from breaking down; useful for heavy periods, nosebleeds and dental work.
• Factor replacement: concentrates of the missing factor, given before surgery or for bleeds.
• Non-factor therapies: such as emicizumab for hemophilia A.
• Platelet transfusions for severe platelet disorders.
• Hormonal treatments (such as the hormonal IUD or combined pill) to control heavy periods.
• Iron replacement for anemia.

Practical tips

• Tell every doctor and dentist about your diagnosis before procedures.
• Avoid aspirin and NSAIDs unless approved by your hematologist; use acetaminophen (paracetamol) for pain.
• Wear a medical alert bracelet for moderate or severe disorders.
• Register with a hemophilia treatment center if you have a significant disorder.

Frequently asked questions

What are the signs of a bleeding disorder?

Common signs include easy or unexplained bruising, nosebleeds lasting more than 10 minutes, bleeding gums, heavy or long periods, bleeding after dental work or surgery that needs extra treatment, and heavy bleeding after childbirth. Bleeding into joints suggests hemophilia.

How do I get tested for a bleeding disorder?

Start with your primary care doctor, who will ask about your bleeding history and order a blood count and clotting tests. If results or your history suggest a disorder, you will be referred to a hematologist for von Willebrand, factor and platelet function tests.

What is the most common bleeding disorder?

Von Willebrand disease is the most common inherited bleeding disorder, affecting about 1 in 100 people, though most have mild symptoms and many are undiagnosed. Hemophilia is much rarer.

Can heavy periods be a sign of a bleeding disorder?

Yes. Heavy periods, especially since your first period, flooding, large clots or iron deficiency, can be a sign of von Willebrand disease or another bleeding disorder. Up to 1 in 5 women with heavy periods have one. Ask your doctor about testing.

Can you develop a bleeding disorder later in life?

Yes. Acquired bleeding disorders can develop from blood thinners, liver disease, low platelet counts, vitamin K deficiency, cancers and, rarely, autoimmune conditions that attack clotting factors. New bruising or bleeding at any age should be checked.