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What tests are reliable in diagnosing bleeding disorders?

For von Willebrand disease, the following tests permit an accurate diagnosis:

For platelet function disorders, the following tests permit an accurate diagnosis:

For hemophilia A and B, the following tests permit an accurate diagnosis:

Because the other clotting factor deficiencies are so rare, tests are first done to rule out von Willebrand disease, platelet function disorders, and hemophilia A and B as the cause of bleeding. If one of the rare factor deficiencies is suspected, a laboratory assay is done to measure the level of the specific clotting factor.

Where are these tests done?

These tests are done in a lab which specializes in bleeding disorders. Most hemophilia / bleeding disorder clinics offer this service.

It is extremely important for a woman who suspects she has a bleeding disorder to go to a hemophilia / bleeding disorder clinic for testing. People at such a clinic know that tests often need to be repeated to get a correct diagnosis. This is because test results can be affected by:
  • normal hormonal changes that happen during a woman's monthly cycle
  • recent use of aspirin or other pain-killers
  • birth control pills, hormone therapy, pregnancy, breast feeding, or recent child birth
  • strenuous exercise, stress or emotional upset just before having blood drawn
  • variation in the lab technologist's technique
  • blood type (Women with blood type O have naturally lower levels of von Willebrand factor and factor VIII than women with blood types A, B or AB.).

Because of these testing difficulties, many women have been told they have no bleeding disorder when, in fact, they do.