DDx ⬇
- Atelectasis
- Chronic pleural thickening
- Lobar consolidation
- Subdiaphragmatic process
Related DDx ⬆ ⬇
Etiology ⬆
Transudates
- Congestive heart failure (most common)
- Cirrhosis with ascites
- Nephrotic syndrome
- Peritoneal dialysis
- Myxedema
- Acute atelectasis
- Constrictive pericarditis
- Superior vena cava obstruction
- Pulmonary embolism
- Urinothorax (due to obstructive uropathy)
Exudates
- Pneumonia (parapneumonic effusion)
- Cancer
- Pulmonary embolism
- Empyema
- Tuberculosis
- Connective tissue disease (eg, rheumatoid arthritis)
- Viral infection
- Fungal infection
- Rickettsial infection
- Parasitic infection (eg, Paragonimus)
- Asbestos
- Meigs' syndrome
- Pancreatic disease
- Uremia
- Chronic atelectasis
- Trapped lung
- Chylothorax
- Sarcoidosis
- Drug reaction
- Post-myocardial infarction syndrome
- Esophageal rupture