[The appropriate use of clinical biological tests in hypercoagulability]

Biological markers who are associated with hypercoagulability are of two types: Markers of activation: among them, the most interesting are the D-dimers which are good tools of diagnostic for the deep venous thrombosis and the pulmonary embolism. Thanks to their high negative predictive value. Etiological factors of hypercoagulable states and thrombosis, in other words: the "hypercoagulability chek up". This one should never be systematic. We propose either to practice it one month after the end of the anticoagulant therapy or to make it with prophylactic doses of low molecular weight heparin and far from the thrombotic episode.