Differential Diagnosis for Ascites
The following list provides a comprehensive differential diagnosis for ascites, categorized for clarity and emphasis on critical considerations.
Single Most Likely Diagnosis
- Cirrhosis: This is the most common cause of ascites, particularly in patients with a history of liver disease or risk factors such as alcohol abuse or hepatitis. Cirrhosis leads to portal hypertension, which is a primary mechanism for the development of ascites.
Other Likely Diagnoses
- Peritoneal Carcinomatosis: Metastatic cancer to the peritoneum can cause ascites due to the obstruction of lymphatic and venous drainage. This is a common cause in patients with known abdominal or pelvic malignancies.
- Heart Failure: Right-sided heart failure can lead to ascites due to increased venous pressure causing fluid leakage into the peritoneal cavity. This is often seen in conjunction with peripheral edema.
- Nephrotic Syndrome: Severe proteinuria can lead to hypoalbuminemia, reducing oncotic pressure and causing fluid to shift into the peritoneal space.
- Tuberculous Peritonitis: In endemic areas, tuberculosis can cause ascites through peritoneal infection, often presenting with abdominal pain and fever.
Do Not Miss Diagnoses
- Spontaneous Bacterial Peritonitis (SBP): Although not the most common cause, SBP is a medical emergency that requires prompt diagnosis and treatment. It typically occurs in patients with cirrhosis and can present with fever, abdominal pain, and altered mental status.
- Ovarian Torsion: While rare, ovarian torsion can cause ascites and is a surgical emergency. It presents with severe abdominal pain and can lead to necrosis of the ovary if not promptly treated.
- Budd-Chiari Syndrome: This condition, caused by hepatic vein thrombosis, can lead to ascites due to post-hepatic venous obstruction. It's crucial to diagnose early to prevent liver failure.
Rare Diagnoses
- Pancreatic Ascites: Leakage from a pancreatic pseudocyst or fistula can cause ascites rich in amylase.
- Chylous Ascites: Due to obstruction or disruption of the lymphatic system, chylous ascites contains high levels of triglycerides.
- Eosinophilic Ascites: Rarely, eosinophilic gastroenteritis or other conditions can cause ascites with a high eosinophil count.
- Sclerosing Encapsulating Peritonitis: A rare condition characterized by thickening of the peritoneal membrane, leading to bowel obstruction and ascites.