Empyema is a condition that causes pus to develop in your pleural space. Pneumonia is the most common cause. A healthcare provider can diagnose empyema by listening to your lungs and ordering imaging and blood tests. Antibiotics treat most cases of empyema, but a provider may need to drain pus with a needle or through surgery.


Your pleural space is a hollow, empty cavity between your lungs and underneath your chest.
Empyema causes pus to develop in your pleural space — the hollow cavity between your lungs and chest wall.

What is empyema?

Empyema is an infection in which pus develops in your pleural space.

Pus is a thick, discolored (white, yellow, pink or green) fluid that your body creates to help fight infection. It consists of white blood cells, dead tissue and bacteria.

Your pleural space is a hollow area (cavity) between your lungs and underneath your chest wall.

Without proper treatment, empyema can get worse and may be fatal. If you have symptoms of empyema, call a healthcare provider right away.

Other names for empyema include pyothorax and purulent pleuritis.

Is empyema a COPD?

No, empyema isn’t a chronic obstructive pulmonary disease (COPD). COPD is an umbrella term for various lung diseases, including chronic bronchitis and emphysema. Healthcare providers are more likely to see infections such as empyema as a symptom in people with COPD than in people without COPD.


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Who does empyema affect?

Anyone can get empyema. However, you’re more likely to get empyema if you:

  • Have pneumonia.
  • Are older than 70.
  • Recently had surgery on your chest.
  • Have diabetes.
  • Have COPD.
  • Have bronchiectasis.
  • Have a blood clot.
  • Inject drugs into a vein with a needle (IV drug use).

How common is empyema?

Empyema isn’t common. There are about 32,000 cases of empyema in the United States each year.

Symptoms and Causes

What are the symptoms of empyema?

Empyema symptoms are nonspecific and may include:


What causes empyema?

Empyema typically develops when an infection spreads from your lungs to the pleural space.

The most common cause of empyema is pneumonia. Other causes include:

How quickly does empyema develop?

Empyema typically develops about four to six weeks after bacteria enter your lungs.

Is empyema contagious?

No, empyema isn’t contagious. However, many of the infections that cause empyema are contagious, especially pneumonia and tuberculosis.


Diagnosis and Tests

How is empyema diagnosed?

A healthcare provider can diagnose empyema. They’ll review your medical history and conduct a physical examination. They’ll also collect a fluid sample from around your lung.

If a provider suspects you have empyema, they’ll order tests to help confirm a diagnosis.

What tests will be done to diagnose empyema?

A healthcare provider may order the following tests to help diagnose empyema:

  • Imaging tests. X-rays and a CT scan help your provider see if there’s fluid in your pleural space. An ultrasound helps show how much fluid you have in your pleural space and helps guide the fluid sample collection. They’ll then send the fluid sample to a lab for analysis and cultures.
  • Blood tests. During a blood test, a provider will use a thin needle to withdraw a small amount of blood from a vein in your arm. They’ll use the sample to look for a high white blood cell count and conduct a C-reactive protein (CRP) and a bacteria culture.

Management and Treatment

Can empyema be cured?

Yes, there’s a cure for empyema. Treatment includes removing pus from your pleural space and treating the infection, usually with antibiotics.

A provider will remove pus through thoracentesis in the early stages of empyema. They’ll use a thin needle to inject a local anesthetic into your skin and deeper tissue. They’ll then attach a larger needle/catheter device to withdraw the pus and drainage tubing to allow the pus to flow outside your body. If drainage isn’t enough, a provider may try to break up the pus through fibrinolytic therapy.

In the later stages of empyema, a provider may need to perform a more invasive procedure, such as surgically removing fibrous tissue (decortication), a thoracotomy or a video-assisted thoracic surgery (VATS).

What medications treat empyema?

A healthcare provider will prescribe antibiotics to treat mild cases of empyema. Examples include, but not limited to, the following:

  • Amoxicillin-clavulanate.
  • Piperacillin-tazobactam.
  • Imipenem.
  • Meropenem.

How soon after treatment will I feel better?

Antibiotics typically take two to six weeks to work. If your provider prescribes antibiotics to treat empyema, it’s important to take your full course of antibiotics, even if you feel better. If you don’t, the cause of your empyema can come back and be more difficult to treat.

After thoracentesis, you may feel sore for a few days or up to a week.

More invasive treatment procedures may require four to six weeks of recovery.


How can I prevent empyema?

The best way to prevent empyema is to treat any lung infections quickly.

Outlook / Prognosis

What can I expect if I have empyema?

Empyema isn’t common. Most cases don’t progress to later stages with early treatment. However, it can be fatal without proper treatment in 5% to 30% of people with empyema and other conditions (comorbidities). The mortality rate is about 40% in immunocompromised people who have empyema.

It’s important to see a healthcare provider if you have symptoms of empyema. If a provider prescribes antibiotics, finish the entire course so the infection doesn’t come back.

Living With

What questions should I ask a healthcare provider?

  • How do you know I have empyema?
  • If I don’t have empyema, what other condition might I have?
  • How did I get empyema?
  • How serious is my empyema?
  • What kind of treatment do you recommend?
  • For how long and at what times of day should I take antibiotics?
  • How should I store my antibiotics?
  • Do I need to schedule follow-up appointments?

Additional Common Questions

What is the difference between pneumonia and empyema?

Pneumonia is an infection in one or both of your lungs. Its causes include bacteria, viruses and fungi. You can cough out infected phlegm if you have pneumonia.

Empyema is an infection in your pleural space. The bacteria that cause pneumonia can cause empyema. You can’t cough out pus if you have empyema. You must clear the pus with antibiotics, or a healthcare provider must drain it with a needle or surgery.

What is the difference between empyema and an abscess?

A lung abscess is an abnormal growth of dead tissue and pus within the lung itself. Pulmonary (lung) infections cause abscesses. Abscesses don’t move. Empyema is pus outside of the lung within the pleural space.

What is the difference between empyema and pleural effusion?

Pleural effusion is a build-up of excess fluid between the thin membranes of your lungs and pleural space. Another name for pleural effusion is water on the lungs.

What is the difference between empyema and parapneumonic effusion?

A parapneumonic effusion is a type of pleural effusion. It develops as a result of pneumonia. It can progress to empyema.

A note from Cleveland Clinic

Empyema is a condition in which you have pus in your pleural space. It usually causes symptoms that affect your chest and breathing. Though it’s not common, if a healthcare provider diagnoses empyema early, your chances of making a full recovery are good. However, empyema can be fatal if you don’t receive treatment or have other conditions.

Talk to a healthcare provider if you have trouble breathing or other symptoms that affect your chest. They can diagnose empyema, determine its cause and work with you to get the most effective treatment.

Medically Reviewed

Last reviewed on 10/05/2022.

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