Portal vein problems might be caused by portal hypertension - cirrhosis, malignancy or hypercoagulable - prothrombotic conditions, malignancy, oral contraceptive pill, pregnancy, trauma.
Portal vein thrombosis may present with many things including abdominal pain, nausea and fever, variceal bleeding, and encephalopathy - or be completely asymptomatic.
Treatment includes observation, anticoagulation, thrombectomy and shunts. Need to prevent thrombus extension and mesenteric ischaemia. May present as an acute ischaemic bowel.