Empyema is caused by an infection that spreads from the lung and leads to an accumulation of pus in the pleural space. The infected fluid can build up to a quantity of a pint or more, which puts pressure on the lungs, causing shortness of breath and pain. Risk factors include recent pulmonary (lung) conditions including bacterial pneumonia, lung abscess, thoracic surgery, trauma or injury to the chest, or rarely, thoracentesis (a needle inserted through the chest wall to draw off fluid in the pleural space).

• A dry cough
• A fever and chills
• Excessive sweating, especially night sweats
• General discomfort, uneasiness, or ill feeling (malaise)
• Unintentional weight loss
• Chest pain, worse on deep inspiration (inhalation)

Abnormal findings, such as decreased breath sounds or a friction rub, may be noted when listening to the chest with a stethoscope (auscultation).

Tests may include the following:

• Chest x-ray
• Thoracentesis
• Pleural fluid gram stain and culture

The goal of treatment is to cure the infection and remove the collection of pus from the lung. Antibiotics are prescribed to control the infection. A doctor will place a chest tube to completely drain the pus. A surgeon may need to perform a decortication (peeling away the lining of the lung) if the lung does not expand properly.

Usually, empyema does not result in permanent pulmonary damage.

A possible complication is pleural thickening.

Call your health care provider if symptoms of empyema develop.

Prompt treatment of pulmonary (lung) infections may prevent some cases of empyema.