- Cirrhosis related--> most common and typically does not require rx/addl eval
- Malignancy related: HCC, pancreatic, biliary, lymphoma, other
- Hyper-coaguable state: factor 5 leiden mutation, lupus anticoagulant, Protein C or Protein S deficiency, prothrombin mutation
- Myeloproliferative d/o: polycythemia vera, essential thrombocytosis, other
- Inflammation for nearby infection
- Abdominal pain, in particular if clot extends into mesenteric veins--> mesenteric venous ischemia