What is the main cause of ascites?

The primary cause of ascites is the pressure build-up in the veins of the liver, a condition often referred to as portal hypertension. This occurs when there is an obstruction or increased resistance in the blood flow through the liver, which can be caused by several underlying conditions such as liver cirrhosis, hepatitis, or tumors. When the pressure in the portal vein rises, fluid leaks from the blood vessels into the abdominal cavity, leading to the accumulation of fluid known as ascites.

This pathophysiological mechanism explains why portal hypertension is a central factor in the development of ascites. In patients with liver disease, the normal balance of fluid production and absorption is disrupted, resulting in the characteristic distention of the abdomen due to accumulated fluid. Understanding this concept is crucial for the appropriate management and treatment of patients with ascites, often involving addressing the underlying liver condition or managing fluid balance.