The most common cause of ascites is portal hypertension secondary to chronic liver disease, which accounts for over 80% of patients with ascites
injection drug use, a history of viral hepatitis or jaundice, and birth in an area endemic for hepatitis. A history of cancer or marked weight loss arouses suspicion of malignant ascites. Fevers may suggest
nonportal hypertensive ascites include infections (tuberculous peritonitis), intra-abdominal malignancy, inflammatory disorders of the peritoneum, and ductal disruptions (chylous, pancreatic, biliary
pericarditis. A large tender liver is characteristic of acute alcoholic hepatitis or Budd-Chiari syndrome (thrombosis of the hepatic veins). Large abdominal wall veins with cephalad flow suggest portal hypertension; inferiorly directed flow implies hepatic vein obstruction The physical examination is relatively insensitive for detecting ascitic fluid. In general, patients must have at least 1500 mL of fluid to be detected reliably by this method
A PMN count of > 250/mcL (0.25 × 109/L) (neutrocytic ascites) with a PMN percentage of > 75% of all white cells is highly suggestive of bacterial peritonitis, either spontaneous primary peritonitis or secondary peritonitis (due to an intra-abdominal source of infection, eg, a perforated viscus or appendicitis