Pleural Effusion is not a disease but rather a complication from an underlying illness.

Transudate pleural effusions are formed when fluid leaks from blood vessels into the pleural space. Chemically, this fluid is clear and contains less protein than exudative pleural effusions.

Common causes of transudative effusions include:

• Congestive heart failure
• Nephritic syndrome or kidney failure
• Cirrhosis of the liver or liver failure
• Pulmonary embolism
• Hypothyroidism

In Exudative effusions, the fluid is often cloudy and is high in protein. This is more serious than transudative effusions. They are formed as a result of inflammation of the pleura itself and are often due to disease of the lung.

Common causes of exudative effusions include:

• Pneumonia
• Lung cancer, or other cancers
• Connective tissue diseases, including rheumatoid arthritis and systemic lupus erythematosus
• Asbestosis and mesothelioma
• Tuberculosis
• Radiotherapy

Symptoms

• (Dyspnea ) Shortness of breath is the most common symptom of a pleural effusion.
• Cough – Some patients will have a dry, non-productive cough.
• Chest pain may occur because the pleural lining of the lung is irritated. The pain is usually
  described as pleuritic, defined as a sharp pain, usually with a deep breath which worsen with coughing.
• Rapid Breathing – Excessive amounts of such fluid can impair breathing by limiting the expansion of the lungs during ventilation, causing the patient to take many breaths so as to get enough oxygen.
• Hiccups
• Fever, chills or sweating

Occasionally a patient will have no symptoms at all. This is more likely when the effusion results from recent abdominal surgery, cancer, or tuberculosis.