This is a medical question of type : exams and tests 
 How to diagnose Von Willebrand Disease ? 
 Early diagnosis of von Willebrand disease (VWD) is important to make sure that you're treated and can live a normal, active life.
                
Sometimes VWD is hard to diagnose. People who have type 1 or type 2 VWD may not have major bleeding problems. Thus, they may not be diagnosed unless they have heavy bleeding after surgery or some other trauma.
                
On the other hand, type 3 VWD can cause major bleeding problems during infancy and childhood. So, children who have type 3 VWD usually are diagnosed during their first year of life.
                
To find out whether you have VWD, your doctor will review your medical history and the results from a physical exam and tests.
                
Medical History
                
Your doctor will likely ask questions about your medical history and your family's medical history. He or she may ask about:
                
Any bleeding from a small wound that lasted more than 15 minutes or started up again within the first 7 days following the injury.
                
Any prolonged, heavy, or repeated bleeding that required medical care after surgery or dental extractions.
                
Any bruising with little or no apparent trauma, especially if you could feel a lump under the bruise.
                
Any nosebleeds that occurred for no known reason and lasted more than 10 minutes despite pressure on the nose, or any nosebleeds that needed medical attention.
                
Any blood in your stools for no known reason.
                
Any heavy menstrual bleeding (for women). This bleeding usually involves clots or lasts longer than 7 to 10 days.
                
Any history of muscle or joint bleeding.
                
Any medicines you've taken that might cause bleeding or increase the risk of bleeding. Examples include aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), clopidogrel, warfarin, or heparin.
                
Any history of liver or kidney disease, blood or bone marrow disease, or high or low blood platelet counts.
                
Physical Exam
                
Your doctor will do a physical exam to look for unusual bruising or other signs of recent bleeding. He or she also will look for signs of liver disease or anemia (a low red blood cell count).
                
Diagnostic Tests
                
No single test can diagnose VWD. Your doctor may recommend one or more blood tests to diagnose the disorder. These tests may include:
                
Von Willebrand factor antigen. This test measures the amount of von Willebrand factor in your blood.
                
Von Willebrand factor ristocetin (ris-to-SEE-tin) cofactor activity. This test shows how well your von Willebrand factor works.
                
Factor VIII clotting activity. This test checks the clotting activity of factor VIII. Some people who have VWD have low levels of factor VIII activity, while others have normal levels.
                
Von Willebrand factor multimers. This test is done if one or more of the first three tests are abnormal. It shows the structure of your von Willebrand factor. The test helps your doctor diagnose what type of VWD you have.
                
Platelet function test. This test measures how well your platelets are working.
                
You may have these tests more than once to confirm a diagnosis. Your doctor also may refer you to a hematologist to confirm the diagnosis and for followup care. A hematologist is a doctor who specializes in diagnosing and treating blood disorders.