The diagnosis of<unk><unk><unk>  (vWD) begins with a relevant personal or family history of mucocutaneous bleeding. When vWD is suspected, several levels of testing are needed in order to make diagnosis. Initial tests involve measurement of vWF antigen (VWF:Ag) level, Factor VIII activity (FVIII:C) and vWF–ristocetin cofactor activity [VWF:RCo]. When the results of all first-level tests are normal, vWD is ruled out; because of biologic variability, however, the tests should be repeated if values are at the low end of the normal range or if vWD is strongly suspected. Persons with a bleeding tendency who have vWF levels between 30 and 50 IU per deciliter are classified as having “low vWF” or “possible type 1<unk> ” but are not classified as having definitive vWD. When<unk><unk>  factor antigen is undetectable (or the level is <5 IU per deciliter, according to the latest<unk>  classification), type 3<unk><unk><unk>  is diagnosed. If these first-level tests reveal definitive abnormalities, a diagnosis of vWD can be made; if the results are not conclusive, second-level tests are required. Second level testing involves repeating the initial tests and then measurement of vWF multimer distribution using gel electrophoresis and ristocetin-induced platelet aggregation (RIPA). Other tests performed in any patient with bleeding problems include: complete blood count (especially platelet counts), APTT (activated partial thromboplastin time), prothrombin time, thrombin time, fibrinogen level, testing for factor IX if hemophilia B is suspected and other coagulation factor assays may be performed depending on the results of a coagulation screen. Patients with<unk><unk><unk>  will typically display a normal prothrombin time and a variable prolongation of partial thromboplastin time.
Von Willebrand disease laboratory findings
Antiphospholipid syndrome laboratory findings
Glanzmann's thrombasthenia laboratory findings
Heparin-induced thrombocytopenia laboratory findings
Disseminated intravascular coagulation laboratory findings
Hemophilia A laboratory findings
Thrombophilia laboratory findings
Portal vein thrombosis laboratory findings