Portal venous pressure is the blood pressure

Blood pressure

Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

 in the portal vein. It is normally 5–10 mm Hg.

An elevated pressure may cause portal hypertension

Portal hypertension

In medicine, portal hypertension is hypertension in the portal vein and its tributaries.It is often defined as a portal pressure gradient of 10 mmHg or greater.-Causes:Causes can be divided into prehepatic, intrahepatic, and posthepatic...

.

It is used in order to calculate hepatic vein pressure gradient(HVPG).

Wedged hepatic venous pressure (WHVP)

Wedged hepatic venous pressure is an estimation of portal venous pressure in alcoholics. In non-alcoholics, however, it underestimates portal venous pressure.