What Is a Lung Abscess?

Medically Reviewed by Melinda Ratini, MS, DO on April 18, 2023
Written by WebMD Editorial Contributors
3 min read

A lung abscess is a pus-filled cavity in your lung surrounded by inflamed tissue. It usually results from breathing bacteria that normally live in your mouth or throat into the lungs, leading to an infection.

Symptoms of a lung abscess commonly come slowly over weeks. They may include:

 

A number of things can cause a lung abscess, including:

Not being able to cough: This often happens as a result of:

  • Anesthesia
  • Alcohol or drug use
  • Nervous system diseases
  • Sedation

Poor oral health: People with gum disease are more likely to get an abscess.

Your immune system isn’t working well: This can let in germs that aren’t usually found in your mouth or throat, like fungi or the bacteria that cause tuberculosis, strep throat, and MRSA.

Blocked airway: Mucus can form behind a tumor or foreign object in your windpipe and lead to an abscess. If bacteria get into the mucus, the blockage stops you from coughing it out.

Blood-borne causes: It’s rare, but bacteria or infected blood clots from an infected part of your body can travel through your bloodstream and into your lung, where they cause an abscess.

A lung abscess is typically diagnosed in two ways:

  • Chest X-ray: This shows your doctor the location of the abscess.
  • CT scan of the chest: Your doctor is looking for an air- and fluid-filled cavity in the middle of your lung. 

The doctor might also use a device called a bronchoscope, a thin tube with a light and a camera on the end, to get samples of sputum or lung tissue for more tests if:

  • Antibiotics aren’t helping.
  • They think your airways are blocked.
  • Your immune system is damaged.

 

There are several ways to treat a lung abscess:

  • Antibiotics: Most people get antibiotics into a vein for up to 3-8 weeks. You might switch to oral antibiotics after that. You’ll take them until a chest X-ray shows the abscess is gone.
  • Drainage: You may need this if your abscess is 6 centimeters or more in diameter. Your doctor will use a CT scan to guide them as they insert the drain through your chest wall into the abscess.
  • Surgery: It’s rare, but some people need surgery to remove the part of the lung with the abscess. Sometimes the entire lung has to come out to get rid of the infection. Surgery can also help remove a foreign object.

 

Possible complications of a lung abscess include:

  • Chronic abscess: That’s what it’s called if it lingers for more than 6 weeks.
  • Empyema: This is when an abscess breaks into the space between your lungs and chest wall and fills the space with pus.
  • Bleeding: It’s rare, but sometimes an abscess can destroy a blood vessel and cause serious bleeding.
  • Bronchopleural fistula: This is an opening between the tubes in your lungs and layers that cover them.

 

Antibiotic treatments will help most people make a full recovery. And the earlier you get treatment, the better. It may be harder to bounce back if you’re weak, ill, have an impaired immune system, or have a tumor that blocks your airways.