Lung Abscess

A lung abscess is an area of pus and dead tissue in your lung. It may have a thick, hard shell with liquid inside. The liquid is a mixture of dead tissue, white blood cells and bacteria. Abscesses are usually one large area, but can also be many smaller pockets.

Lung abscesses are most often caused by bacterial infections. Sometimes, fungal infections can cause them. Primary lung abscesses happen without other health conditions causing them. They often happen after aspirating (accidentally inhaling) food or stomach acid into your lungs. Secondary lung abscesses are a complication of a health condition you already had.

Symptoms of lung abscesses

Symptoms of a lung abscess are similar to other respiratory infections, but may be more severe. They include:

• Fever (this might go up and down in waves)
• Cough
• Coughing up foul-smelling mucus or pus
• Difficulty breathing
• Chest pain
• Night sweats
• Fatigue

Lung abscess causes

Bacterial infections are the most common cause of lung abscesses. They destroy your tissue, making a cavity in your lung. The cavity fills with dead tissue, white blood cells and bacteria.

In primary lung abscesses, the bacteria usually end up in your lung after you aspirate food or stomach acid. Sometimes, lung abscesses are a complication of other conditions — like lung blockages, surgery or a weakened immune system (secondary lung abscess). A weakened immune system reduces your ability to fight infections, which can lead to abscesses.

Fungal infections can also cause lung abscesses. This is more likely in people with weakened immune systems.

Risk factors

Risk factors for lung abscess include:

• Tooth and gum disease
• Alcohol use disorder
• Pneumonia
• Lung obstructions (tumors or foreign objects)
• Recent lung or chest surgery
• Infection in a nearby organ (like endocarditis), which could spread to your lungs
• Conditions that weaken your immune system
• GERD (chronic acid reflux)

These conditions can make it easier for bacteria to get into your lungs. This could be either because you’re more likely to have harmful bacteria in your body or because you’re at a higher risk for aspiration.

Complications of lung abscesses

Large abscesses can lead to lung changes and other complications, including:

• Widening and pouches in your airways (bronchiectasis)
• Pus in the area between your lung and chest wall (empyema)
• Excessive bleeding in your lungs

How doctors diagnose lung abscesses

Providers can often see lung abscesses on chest X-rays or CT scans. This can be enough to diagnose them. They may need additional tests to find the underlying cause of the abscess or the kind of bacteria in it.

Additional tests include:

• Bronchoscopy: Your provider will use a lighted camera to look inside your lungs and get a sample of pus to test.
• Needle biopsy or thoracentesis: Your provider may use one of these procedures to drain or test fluid from your lungs.
• Blood tests: Providers can use blood tests to look for signs of infections.
• Sputum test: You cough, then spit into a tube. A lab tests the sample for bacteria.

How is it treated?

Providers treat lung abscesses with antibiotics. The kind of antibiotics they use depends on whether you have a primary or secondary abscess.

They treat secondary abscesses with an antibiotic that kills the specific bacteria causing the abscess.

If antibiotics don’t work, you may need surgery to treat the abscess or a procedure to drain it. You may need additional treatments for any additional causes, like surgery to remove a blockage in your lungs.

When should I see my healthcare provider?

See your provider if you have symptoms of a lung abscess. It can cause serious complications if left untreated.

When should I go to the ER?

Go to the emergency room or call 911 (or your local emergency service number) if you:

• Have a fever higher than 103 degrees Fahrenheit or 40 degrees Celsius
• Are coughing up blood or anything that smells foul
• Struggle to breathe or are short of breath while sitting still
• Have new or worsening chest pain
• Are confused or can’t think clearly

What can I expect if I have a lung abscess?

Most people with lung abscesses get better with treatment. You’ll need to take antibiotics for weeks or even months to get rid of the infection. Take all your medication as prescribed, even if you feel better. Abscesses larger than 6 centimeters (a little over 2 inches) are more likely to need surgery to cure them.

What is the survival rate of lung abscesses?

Most people survive primary lung abscesses with treatment (studies report a mortality rate around 8.7%). Some factors might make an abscess harder to treat, including:

• The size of the abscess: Abscesses larger than 6 cm are harder to cure with antibiotics alone.
• How long you’ve had symptoms: The longer you’ve had symptoms without treatment, the harder it may be to get rid of the abscess.
• The underlying condition that caused it: For instance, if your immune system can’t fight off the infection, it might take longer or be harder to get rid of.

Can a lung abscess be prevented?

You can reduce your risk of a secondary lung abscess by managing health conditions that can lead to one. You can reduce your risk of primary lung abscess by:

• Taking good care of your oral health
• Avoiding excess alcohol
• Taking steps to avoid acid reflux if you’re at a higher risk for aspiration

Providers can also take steps to reduce your risk of aspiration during and after surgery or while you’re staying in a hospital.

What’s the difference between an empyema and a lung abscess?

An empyema is a collection of pus in the area between your lung and your chest wall (pleural space). A lung abscess is pus inside your lung.