Popcorn lung refers to a rare lung disease that causes scarring and inflammation in the bronchioles. This can cause a persistent dry cough and shortness of breath.

Bronchiolitis obliterans is a rare form of lung disease. It’s commonly called popcorn lung.

Popcorn lung results in scarring and inflammation to the bronchioles. These are the lung’s smallest airways. When they’re inflamed, symptoms like coughing, shortness of breath, and difficulty breathing can occur.

popcorn lung CT scan
A CT scan of someone with popcorn lung. Image courtesy of Xie, B-Q, et al./PLOS

“Popcorn lung” may sound strange, but there’s a reason behind the name. Workers in a popcorn factory became sick after breathing in harmful chemicals.

One of those chemicals is diacetyl. It’s an artificial butter-flavored ingredient found in:

  • popcorn
  • flavored coffee
  • fruit drinks
  • caramel
  • some dairy products

While the Food and Drug Administration (FDA) considers diacetyl generally safe to eat, it’s dangerous when inhaled.

Many food companies have removed diacetyl from their products, but it’s still found in many electronic cigarette (e-cig) flavors, leading to cases of popcorn lung in people who vape.

Here’s a closer look at common popcorn lung symptoms, other chemicals and medical conditions that can cause it, and how it’s treated.

Symptoms of popcorn lung are similar to those of chronic obstructive pulmonary disease (COPD). Popcorn lung symptoms often occur 2 to 8 weeks after illness or exposure to harmful chemicals, particles, or toxic fumes.

Common symptoms include difficulty breathing and a persistent, progressive, and dry cough.

Once symptoms show up, they often occur regularly. They’re not episodic like asthma symptoms, for example.

Other symptoms may include:

  • flu-like illness with fever
  • unexplained fatigue
  • weight loss
  • wheezing
  • eye, skin, mouth, or nose irritation, if caused by chemical exposure

Get care now

Seek immediate medical attention if your symptoms worsen, or if you experience:

  • difficulty breathing
  • shortness of breath
  • chest pain
  • dizziness
Was this helpful?

Popcorn lung can result from inhalation of certain harmful chemicals, particles, and toxic fumes found in microwave popcorn factories and e-cigarettes.

However, the toxic fumes and chemicals associated with popcorn lung aren’t limited to just these factories or e-cigarettes.

Other chemicals that may contribute to popcorn lung when inhaled include:

  • chlorine
  • ammonia
  • sulfur dioxide
  • nitrogen dioxide
  • fumes from welding
  • acetaldehyde
  • formaldehyde
  • hydrochloric acid
  • phosgene
  • mustard gas

Certain health conditions are linked to popcorn lung as well. Some of these include:

Inflammation and scarring resulting from a lung transplant can also cause popcorn lung.

Typically, it takes 2 to 8 weeks after illness or chemical exposure for symptoms to begin. In other cases, like a lung transplant, it may take several months or years before symptoms appear.

Research from 2016 found that 75 percent of flavored e-cigarettes and refill liquids tested positive for diacetyl — the same chemical responsible for popcorn lung among microwave popcorn factory workers.

If you currently vape and are unable to stop, you may want to consider foregoing flavored options.

Still, even flavorless e-cigarettes are linked to an increased risk of respiratory disease. Plus, e-cigarette vapor also contains formaldehyde, another chemical linked to popcorn lung.

Ready to kick a vaping habit? Our guide can help.

Popcorn lung is often misdiagnosed as asthma, bronchitis, or emphysema, so be sure to bring up your concerns to a healthcare professional if you think you might have popcorn lung. Let them know if you use e-cigarettes or have been exposed to chemicals linked to popcorn lung.

To diagnose popcorn lung, your doctor will order a chest X-ray or CT scan. They may also use a pulmonary function test. This test measures how well your lungs are functioning.

The most definitive way to diagnose popcorn lung is a surgical lung biopsy.

General anesthesia may be needed for this type of biopsy so you don’t feel any pain. Your surgeon will make an incision on your chest and remove a piece of lung tissue. They’ll then send the lung sample to a lab for analysis.

Your doctor will help determine which method of diagnosis is best for your situation.

There’s currently no cure for popcorn lung, but there are treatments to help alleviate symptoms. Treatment may also help slow the progression of the disease.

One option for treatment is prescription corticosteroids. Your doctor may also recommend immunosuppressant therapy to decrease your body’s immune response.

Depending on your symptoms, your doctor may also prescribe:

  • cough suppressants
  • bronchodilators (medication that helps open the airways)
  • oxygen supplementation, if needed

Some people living with severe cases of popcorn lung are candidates for a lung transplant. However, popcorn lung may develop again as a complication of the transplant.

If left untreated, popcorn lung can be fatal in some cases.

To prevent popcorn lung, you’ll need to avoid or limit your exposure to chemicals linked to the condition. You can do this by:

  • not using e-cigarettes
  • ensuring proper controls are in place if you encounter these chemicals at work
  • wearing personal protective equipment when exposed to these chemicals

If you’re having trouble quitting vaping or e-cigarettes, you have options:

  • Talk with a healthcare professional to set up a quit plan.
  • Call 800-QUIT-NOW (800-784-8669) for free coaching.
  • Visit Smokefree.gov for tools and tips.
  • Prefer text-based support? Enroll in SmokefreeTXT to receive daily text messages to help you quit vaping.

While popcorn lung is an irreversible condition, treatment can help you manage your symptoms.

The best way to prevent popcorn lung is to limit exposure to harmful toxins and chemicals. Make sure you’re protected at work, and, if you smoke, quit smoking, including e-cigarettes and vaping devices.

Many people find it hard to quit on their own. It may take multiple tries, too. That’s OK — don’t give up. And don’t hesitate to reach out for extra help from your care team or community resources.