[Venous thromboembolism. Introduction].

The main aim of the treatment of deep venous thrombosis (DVT) is to prevent the onset of the main complications: embolism (acute) and post-phlebothrombotic syndrome-PPS--(late complication). If not treated, during the acute phase DVT presents extension and/or embolism in 60% of cases and pulmonary embolism is potentially fatal in 5-10%. PPS is the most frequent complication (up to 70% of cases). The treatment of acute DVT has been based for over thirty years on heparin and oral anticoagulants: thrombolytic agents and low molecular weight (LMWH) heparins have been introduced more recently. Anticoagulants treatment is continued for 3-6 months (or longer in the event of recidivation or thrombophilia). LMWH have proved more effective and easier to manage than non-fractioned heparin. The association of thrombolytic and heparin presents no advantages compared to the use of heparin alone. It is currently reserved for cases of venous gangrene and acute massive pulmonary embolism. The possibility of surgical embolectomy or the use of catheters should only be considered in treatment is ineffective or contraindicated. The aim of this paper is to analyse the treatment of DVT and the diagnostic, clinical, laboratory and instrumental procedures used, and to describe the most up-to-date indications for its diagnosis and treatment.