**Question:** Normal portal vein pressure is

A. 8-16 mmHg
B. 16-20 mmHg
C. 10-15 mmHg
D. 12-15 mmHg

**Core Concept:** Portal hypertension is a condition characterized by elevated portal vein pressure resulting from increased resistance in the portal venous system. The portal vein is a branch of the superior mesenteric vein, carrying deoxygenated blood from the intestines back to the liver for further purification.

**Why the Correct Answer is Right:** Normal portal vein pressure is crucial for understanding the pathophysiology of portal hypertension. In a healthy liver, portal vein pressure typically ranges from 12-15 mmHg. The answer D falls within this normal range, making it correct.

**Why Each Wrong Option is Incorrect:**

A. 8-16 mmHg (Option A) is too low, indicating that the liver is functioning efficiently without signs of portal hypertension.
B. 16-20 mmHg (Option B) is still higher than the normal range and indicates early stages of portal hypertension.
C. 10-15 mmHg (Option C) is within the normal range, but the correct answer is slightly lower, indicating that this option is close but not precise.

**Clinical Pearl / High-Yield Fact:** Portal hypertension can lead to serious complications, such as variceal bleeding, ascites, and splenomegaly. Early detection and monitoring of portal hypertension is essential to prevent these complications.

**Answer Explanation:** Portal hypertension develops when the resistance in the portal vein system increases, leading to elevated portal vein pressure. Monitoring portal vein pressure helps in identifying and managing patients at risk of developing portal hypertension-related complications.