[Diagnosis of thrombophilia]].

Using laboratory testing, coagulation alterations can be detected in about 50% of familial thrombophilia. Most common hereditary coagulation defects leading to enhanced thrombosis risk are aPC resistance/Factor V Leiden mutation, protein C- and S-deficiency, prothrombin 20210A polymorphism and antithrombin deficiency. Moreover, elevated plasma levels of homocysteine also are associated with enhanced thrombosis risk. Severity of thromboembolic risk depends upon type of coagulation defect, hetero- or homocygosity and occurrence of additional acquired risk factors like immobilisation. Therapy of thromboembolic diseases must always be planned considering both clinical circumstances and laboratory findings.