Cirrhosis: This is the most common cause of ascites, particularly in patients with a history of liver disease, alcohol abuse, or viral hepatitis. The liver damage leads to portal hypertension, which causes fluid to leak into the peritoneal cavity.

Heart Failure: Right-sided heart failure can lead to increased pressure in the hepatic veins, causing fluid to accumulate in the peritoneum.
Peritoneal Carcinomatosis: Metastatic cancer to the peritoneum can cause ascites due to the production of malignant effusions.
Nephrotic Syndrome: Severe proteinuria can lead to hypoalbuminemia, resulting in decreased oncotic pressure and fluid accumulation in the peritoneum.
Tuberculous Peritonitis: Infection with Mycobacterium tuberculosis can cause ascites, particularly in endemic areas or in immunocompromised patients.

Spontaneous Bacterial Peritonitis (SBP): Bacterial infection of the ascitic fluid can occur in patients with cirrhosis and ascites, and is a medical emergency requiring prompt antibiotic treatment.
Ovarian Torsion: A rare but potentially life-threatening condition that can cause ascites, particularly in women with ovarian cysts or tumors.
Budd-Chiari Syndrome: Thrombosis of the hepatic veins can cause ascites, abdominal pain, and liver dysfunction, and requires prompt anticoagulation and possible intervention.

Lymphatic Disorders: Conditions such as lymphangiectasia or lymphoma can cause ascites due to impaired lymphatic drainage.
Pancreatic Ascites: Leakage of pancreatic secretions into the peritoneum can cause ascites, often in the setting of pancreatitis or pancreatic pseudocyst.
Chylous Ascites: Accumulation of lymphatic fluid in the peritoneum can cause ascites, often due to lymphatic obstruction or trauma.
Eosinophilic Peritonitis: A rare condition characterized by eosinophilic infiltration of the peritoneum, often associated with parasitic infections or hypereosinophilic syndrome.