Common etiologies for intrahepatic hepatic vein thrombosis include hypercoagulable states (such as anti-phospholipid antibody syndrome, protein S deficiency, protein C deficiency, and antithrombin III deficiency) and myeloproliferative diseases. Inflammatory diseases such as Behcet’s syndrome or inflammatory bowel disease may also cause Budd- Chiari Syndrome. Inferior vena cava thrombosis, which may be caused by hypercoagulable states in many cases, is as yet of unknown cause. One recent theory proposes that compression of the inferior vena cava during diaphragm motion induces thrombus formation.
