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Empyema

Medically Reviewed.Last updated on 05/21/2026.

Empyema causes pus to develop in the pleural space in your chest. The most common cause is pneumonia. Healthcare providers can diagnose it with imaging and blood tests. Antibiotics can treat most cases. But a provider may need to drain pus with a needle or surgery.

What Is Empyema?

Anatomy of empyema in lungs, with pus in the pleural space, the hollow cavity between the lungs and chest wall
Empyema causes pus to develop in your pleural space, usually when an infection spreads beyond your lungs.

Empyema is an infection in which pus develops in your pleural space. Your pleural space is a hollow area (cavity) between your lungs and underneath your chest wall.

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Empyema (pronounced “em-pie-EE-muh”) causes symptoms that affect your chest. Without proper treatment, your symptoms may get worse and can be deadly. In the U.S., empyema affects up to 65,000 people each year.

Other names for empyema include:

  • Thoracic empyema
  • Empyema thoracis
  • Pyothorax
  • Purulent pleuritis

What are the stages?

There are three stages of empyema development:

  • Stage I (exudative stage): A small amount of fluid builds up in your pleural space after sudden inflammation. The fluid is sterile, which means it doesn’t have any germs in it.
  • Stage II (fibrinopurulent stage): Your immune system recognizes an infection, so pus builds up in pockets of your pleural space.
  • Stage III (organizational stage): When fluid and pus can’t drain, they can become a thick, tough “peel.” The peel can limit how far your lungs can expand.

Symptoms and Causes

Symptoms of empyema

Empyema symptoms are nonspecific. That means they’re too general for your provider to make a diagnosis without testing. They may include:

  • Chest discomfort or pain
  • Fever
  • Trouble breathing
  • Cough
  • Extreme tiredness
  • Unexplained weight loss

What is the main cause of empyema?

Empyema usually develops when an infection within your lung spreads to the area around/outside your lung. The most common infection that causes it is pneumonia.

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Other causes may include:

How quickly does it develop?

If empyema develops, it’s typically about four to six weeks after bacteria enter your lungs.

What are the risk factors?

Anyone can get empyema. But you’re at a higher risk if you have conditions like:

You may also be at risk if you:

  • Are 70 years of age or higher
  • Recently had surgery on your chest
  • Inject drugs into your veins with a needle (IV drug use)

What are the complications?

Empyema complications may include:

  • Pus developing in your pleural space again (recurrence)
  • Scarring in the thin tissues in your pleural space, which limits how much your lungs and ribcage can move when you breathe (fibrothorax)
  • Your lungs can’t hold as much air (restrictive lung disease)
  • An abnormal passageway in your lungs (bronchopleural fistula)
  • You don’t have enough oxygen in your body (respiratory failure)
  • Your immune system overreacts to the infection and damages the rest of your body (sepsis)
  • The infection wears away at your chest wall (empyema necessitans)

Diagnosis and Tests

How doctors diagnose empyema

Your healthcare provider will:

  • Review your medical history
  • Ask about your symptoms
  • Conduct a physical exam, which may involve listening to your lungs with a stethoscope

If they suspect empyema, they’ll recommend tests to help confirm a diagnosis. These may include:

  • Imaging tests: X-rays and a CT scan can help your provider see fluid in your pleural space. An ultrasound helps show how much fluid is in your pleural space.
  • Thoracentesis: Your provider will use a thin needle to collect some fluid from around your lungs. They’ll send the fluid to a lab for analysis and a bacterial culture.
  • Blood tests: Your provider will take a blood sample and send it to a lab. Lab workers will look for a high white blood cell count. They’ll also do a CRP test and a bacterial culture on your sample.

Management and Treatment

How is empyema treated?

Treatment includes removing pus from your pleural space and treating the infection. Providers commonly prescribe antibiotics to kill the infection.

In the early stages of empyema, they’ll do a thoracentesis procedure to remove pus. They’ll numb the area with a local anesthetic. Then, they’ll use a catheter device to withdraw the pus. Often, they’ll place a tube into the chest and leave it there for several days to allow continuous drainage. If drainage isn’t enough, your provider may inject medications into your chest through the tube to break up the pus. This usually requires a hospital stay.

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In the later stages, your provider may need to perform a more invasive procedure to remove fibrous tissue from your lungs and chest wall. These may include:

What antibiotics will they use?

Your healthcare provider may prescribe:

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

Recovery time

Antibiotics usually take two to six weeks to work. It’s important to take your full course of antibiotics, even if you feel better. If you don’t, the infection may come back and be harder to treat.

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

If you need surgery, it may take between four and six weeks to make a full recovery.

When should I see my healthcare provider?

It’s important to see your provider if you have symptoms of empyema and are at a higher risk of getting it.

During your appointment, you may want to ask questions like:

  • If I don’t have empyema, what’s causing my symptoms?
  • How did I get empyema?
  • How serious is it?
  • What kind of treatment do you recommend?
  • What antibiotics do you recommend?
  • How long do I need to take antibiotics?
  • How should I store my antibiotics?
  • Should I schedule follow-up appointments?
  • Are there any signs I should look out for that it has come back?

Outlook / Prognosis

What can I expect if I have empyema?

With early diagnosis and treatment, most empyema cases don’t progress to later stages. Most people make a full recovery.

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Without proper treatment, your risk of permanent lung damage increases. It’s also more likely to be fatal, especially if you have empyema along with other conditions (comorbidities). This includes a weakened immune system.

Additional Common Questions

Is empyema a COPD?

No, it isn’t chronic obstructive pulmonary disease (COPD). “COPD” is an umbrella term for various lung diseases. These include chronic bronchitis and emphysema. If you have COPD, providers are more likely to see an infection like empyema as a symptom than if you didn’t have COPD.

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 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 provider must use a procedure to drain it.

What is the difference between emphysema and empyema?

Emphysema is a lung disease that results from damage to the fragile air sacs (alveoli) in your lungs. Smoking is the main cause of emphysema.

What is the difference between empyema and pleural effusion?

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

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

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A note from Cleveland Clinic

Chest pain, fever, fatigue, a cough — these are symptoms of many kinds of conditions. It can be easy to dismiss how you’re feeling as a common illness or infection. But if a healthcare provider recently diagnosed you with pneumonia or you experienced chest trauma, these may be symptoms of empyema. You should quickly schedule an appointment with your provider to help keep it from progressing. They can also address any of your questions or concerns.

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Medically Reviewed.Last updated on 05/21/2026.

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