Normal portal vein blood pressure is 5-10 mmHg. More precisely, when blood pressure in inferior vena cava (IVC) exceeds 5 mmHg it is called portal hypertension. Portal hypertension develops when there is a blockage in blood flow through liver. In this condition, esophageal, gastric, rectal and umbilical varices develop. Rupture of these varices is life-threatening.