Empyema is a condition that affects the space between the outermost layer of the lungs and the layer touching the chest wall, known as the pleural space. This space exists to help the lungs expand and contract.

The pleural space naturally contains a small amount of fluid. Empyema happens when extra fluid begins to collect in the pleural space.

Different strains of bacteria cause fluid and pus to build up in the pleural space. Very often, pneumonia causes empyema.

In this article, learn more about the symptoms, causes, and risk factors for empyema, as well as the treatment options.


Woman in bed due to pneumonia caused by Empyema
Symptoms of empyema may include chest pain, fever, a cough, and pneumonia that does not improve.

Symptoms of empyema may include:

  • having a case of pneumonia that does not improve
  • a fever
  • chest pain
  • a cough
  • pus in mucus
  • difficulty breathing
  • a crackling sound from the chest
  • decreased breathing sounds
  • dullness when tapping chest
  • fluid in the lungs (visible with a chest X-ray)

Empyema can progress through three stages if a person does not receive treatment.

Stage 1: Simple (the exudative phase)

The first stage of empyema is called simple empyema. It occurs when extra fluid begins to build up in the pleural cavity. This fluid can become infected and may contain pus.

Stage 2: Complicated (the fibrinopurulent phase)

In complicated empyema, the fluid in the pleural cavity begins to thicken and form “pockets.”

Stage 3: Frank (the organizing phase)

Finally, the infected fluid causes scarring to the inner layers that line the pleural cavity in the lungs. This causes difficulty breathing as it stops the lungs from inflating properly.


Pneumonia is the most common cause of empyema. People who have undergone thoracotomies, or chest surgeries, might also be at risk of developing empyema if bacteria get into the wound.

Risk factors

Senior with the flu
A person who is older than 70 and has recently had pneumonia may be at risk of empyema.

The biggest risk factor for empyema is having had pneumonia recently.

Other risk factors include:

  • being older than 70
  • having been in the hospital recently
  • having had chest surgery or trauma

In low-risk populations, empyema was generally less severe, and people were more likely to have developed empyema outside of a hospital.

Statistically, people with the following conditions are also more likely to develop empyema.

  • diabetes
  • heart disease
  • previous cancer
  • chronic obstructive pulmonary disorder (COPD)
  • lung disease
  • intravenous drug use (in simple empyema cases)


The first step to diagnosing empyema is a chest X-ray. An X-ray can only identify empyema when there is a specific amount of fluid in the pleural cavity, however.

If the doctor suspects there is liquid in the pleural cavity after a chest X-ray, they will carry out an ultrasound. Ultrasounds are more sensitive and better at detecting fluid in the pleural cavity.

CT scans are also a useful method of detecting empyema. This allows doctors to see the “pockets” of liquid in the pleural cavity.


Treatment for empyema can include:


Doctors usually prescribe antibiotics as the first treatment for simple cases of empyema. Because different strains of bacteria cause empyema, finding the right antibiotic is crucial.

Antibiotic treatment typically takes 2 to 6 weeks to work.


Draining the fluid is essential to prevent simple empyema progressing to complicated or frank empyema. It also helps keep the condition under control.

To drain the fluid, a doctor performs a tube thoracostomy, which involves inserting an ultrasound or computer-guided tube into the chest cavity and removing the liquid from the pleural space.


surgeons in operating theatre performing crohn s surgery
A doctor may recommend surgery for advanced empyema.

For advanced cases of empyema, surgery may be the best treatment option. One study found that a surgery called decortication yielded better results than tube drainage in people with advanced empyema.

Decortication involves removing the pus “pockets” and fibrous tissue from the pleural space, which helps the lungs expand properly.

There are two types of surgeries available. In most cases, a surgeon will perform a video-assisted thoracotomy (VATS). This procedure is less invasive, less painful, and has a shorter recovery time than an open-thoracotomy, which requires a surgeon to open the chest.

In some cases, however, a surgeon will perform an open-thoracotomy.

There are no specific criteria to decide when surgery is necessary for empyema. One study found that those with symptoms lasting less than 4 weeks had better surgery results than people who had symptoms lasting more than 4 weeks.

Fibrinolytic therapy

A doctor may also recommend fibrinolytic therapy, which uses drugs known as fibrinolytic agents. The therapy helps to drain pleural fluid, and doctors may use it in combination with a tube thoracostomy.

A 2018 study assessing the effectiveness of VATS surgery in comparison to fibrinolytic therapy after tube thoracostomy found that both methods are highly effective.

Rare complications

Possible complications of empyema include:

  • Fibrosis, which is when damaged lung tissue causes difficulty breathing that affects a person’s quality of life. If breathing difficulty continues 6 months after infection, decortication surgery may improve symptoms.
  • Empyema necessitatis, which is an extension of the infection into the chest wall and soft tissue. This is very rare and requires immediate medical attention.


Getting early medical attention can stop empyema from becoming a more severe condition.

Treatment for empyema can vary depending on the severity of a person’s symptoms. Antibiotics and drainage are the first steps, followed by surgery in more advanced cases.