The most common causes of pleural effusion

Pleural effusion can be broadly categorized into infectious and non-infectious types based on etiology. It is a common clinical condition characterized by pathological accumulation of fluid within the pleural cavity. The pleural cavity is a potential space between the visceral and parietal pleurae. Normally, 5–15 mL of fluid exists in this space, serving as lubrication during respiration. Approximately 500–1000 mL of pleural fluid is produced and absorbed daily.

1. Infectious Pleural Effusion

Infectious pleural effusion can result from various bacterial or viral infections, including tuberculosis, fungi, parasites, mycoplasma, and viruses. Common clinical conditions include tuberculous exudative pleuritis, tuberculous empyema, and nonspecific pyothorax. Treatment primarily involves general supportive measures combined with anti-infective therapy.

General treatment: Patients should rest in bed and receive symptomatic medications, electrolyte balance maintenance, and nutritional support.

Anti-infective treatment: Initial empirical therapy with broad-spectrum antibiotics such as penicillins or cephalosporins is recommended. Antibiotics should cover pathogens like streptococci and staphylococci. In addition, pleural effusion drainage may be performed; removing fluid from the pleural cavity can relieve compression symptoms.

2. Non-infectious Pleural Effusion

Heart failure is one of the common causes of pleural effusion. For heart failure-related effusions, diuretics such as furosemide are typically used. In cases of pyogenic pleuritis, chest tube placement for drainage may also be required. If the effusion is caused by malignant tumors such as lung cancer, treatment must target the underlying tumor.

There are numerous potential causes of pleural effusion. Patients should undergo appropriate medical evaluations at a hospital to determine the exact cause and receive targeted, physician-guided treatment.