Pleural Effusion
Overview
The pleura is a thin, double-layered membrane that surrounds the lungs and lines the inside of the chest cavity. Normally, a small amount of pleural fluid acts as a lubricant between these layers to help the lungs move smoothly during breathing. A pleural effusion occurs when an abnormal amount of fluid builds up in the pleural space. It is not a disease in itself, but usually a sign of an underlying medical condition.
Causes / Risk Factors
Pleural effusion can be caused by a wide range of conditions, including infection, cancer, tuberculosis, heart failure and other medical problems.
Causes
- Tuberculosis
- Pneumonia
- Cancer
- Organ failure: heart failure, cirrhosis, renal failure
- Rare: chylothorax, benign asbestos pleural effusion, connective tissue disease
Common Symptoms
- Shortness of Breath: It is the most common symptom, especially during physical activity. It is due the compression of lung by fluid.
- Cough: Usually dry cough, but can be productive cough in tuberculosis or pneumonia.
- Chest Pain: A sharp or dull pain in the chest, which may worsen with deep breaths or coughing. It usually occurs when there is inflammation of pleura.
- Fever: Fever may be present if the effusion is caused by an infection, such as pneumonia or tuberculosis.
Diagnosis
- Chest X-ray: The standard imaging test to show if there is excess fluid present
- Computerized tomography (CT) of thorax: Provides more detailed view of the size of effusion, and the potential cause of it.
- Pleural aspiration: A needle was inserted into pleural cavity to obtain fluid sample for analysis, under local anesthesia and ultrasound guidance.
- Pleural biopsy: Involves removing a small tissue sample for examination.
- Medical thoracoscopy: It is a minimally invasive procedure, a small incision was made at the chest wall, and a pleuroscope is inserted into the pleural cavity for thorough examination. It can allow direct visualization of pleural surface, and take targeted sample over suspicious areas.
Treatment and Management
- As pleural effusion is always secondary to other diseases, obtaining the diagnosis has the highest priority in order to treat pleural effusion.
- Treatment depends on the underlying cause, e.g. anti cancer therapy if cancer patients, anti-TB medication for tuberculosis, antibiotics for pneumonia and diuretics for heart failure.
- For large symptomatic effusion, a chest tube can be inserted to relieve the symptoms.
- For patients with recurrent symptomatic pleural effusion, further procedures such as pleurodesis (procedure to prevent fluid re-accumulation) or insertion of indwelling pleural catheter (for self drainage of fluid at home) can be considered depending on the underlying cause.
Last updated: March 2026