"Popcorn lung" is the nickname for bronchiolitis obliterans. This chronic medical condition can scar the smallest airways of your lungs, making you cough and feel short of breath. It's sometimes caused by breathing in a chemical used to flavor microwave popcorn. But other chemicals, lung illnesses, or autoimmune conditions can also cause popcorn lung.
Your lungs are where your blood picks up oxygen before carrying it to cells in the rest of your body.
When you breathe in, air flows into your lungs through your windpipe or trachea. Your windpipe divides into two tubes called the bronchi, which lead to your left and right lungs. Inside your lungs, those tubes split again and again, like the branches of a tree.
The smallest of those branches are called bronchioles. The bronchioles end in tiny air sacs called alveoli, where oxygen moves into your blood. When you have "popcorn lung," those tiny air passages get irritated and inflamed. The scarring can narrow these passages, making it harder for you to get enough air.
What Causes Popcorn Lung?
Diacetyl
This condition gets its nickname from a chemical called diacetyl. After workers at a factory that packaged microwave popcorn were found to have bronchiolitis obliterans more often than other people, some companies stopped using diacetyl as a flavoring.
But diacetyl is still used in some electronic cigarette flavors in the US. Many e-cigarette makers state they aren't using this chemical in their products, and its use in e-cigarettes is banned in Europe.
Acetaldehyde
Another common cause is acetaldehyde, a chemical found in the smoke from marijuana and some electronic cigarettes. Acetaldehyde can also damage the lining of your mouth, throat, and stomach.
Chemical exposure
Other chemicals that can cause popcorn lung include:
- Metal oxide fumes, a common byproduct of welding
- Formaldehyde, a cancer-causing chemical used in some glues and building materials
- Sulfur dioxide, a pollutant released by burning fossil fuels
- Ammonia
- Chlorine
- Nitrogen oxides
- Hydrochloric acid
- Sulfur mustard, a chemical weapon known as "mustard gas"
Lung problems and autoimmune disease
Sometimes, bronchiolitis obliterans happens after you've had a serious illness affecting your lungs, such as some forms of pneumonia or bronchitis. And some people who have rheumatoid arthritis can get popcorn lung as a side effect of that condition.
If you've had a lung transplant or a stem cell transplant, you may get this condition if your body tries to reject the new organ. It's the primary cause of death in people who get lung transplants.
What Does Popcorn Lung Feel Like?
Popcorn lung is marked by narrower airways, which can make it harder to breathe. That means your body may not get as much oxygen. Without oxygen, you may feel fatigued or like you can't catch your breath after you go up stairs. The main symptoms of popcorn lung include:
- Dry cough
- Feeling tired for no reason
- Shortness of breath, especially after exercise or activity
- Wheezing, without asthma or a cold
How long before symptoms show up?
You may notice symptoms between two weeks and two months after you've been around a toxic gas or had an illness. But if you've had a lung transplant, it might take several years for signs to show up.
When to call the doctor
Popcorn Lung Symptom Checklist | ||
|---|---|---|
Symptom: | Make an Appointment if: | Get Medical Care Right Away if: |
Dry cough | It lasts 8 weeks or more. | You cough up blood. |
Shortness of breath | It happens after activity or exercise. | It gets worse quickly, or if you can't breathe. |
Wheezing | You notice a whistling sound after you exhale. | You have chest pain or severe tightness. |
Fatigue | It's for no reason or malaise | You get confused, dizzy, or pass out. |
How to Diagnose Bronchiolitis Obliterans
If you have some of the symptoms of bronchiolitis obliterans (popcorn lung), your doctor might recommend a CT scan of your chest. Several X-rays are taken from different angles and put together to make a complete picture.
Your doctor may also run tests such as:
- Bronchoscopy to check on lung inflammation
- Chest X-ray to see if your lungs are holding in too much air
- Lung biopsy to confirm your diagnosis, most often done with surgery
- Pulmonary function tests to see how well your lungs are working
Is Popcorn Lung Curable?
There's no cure for popcorn lung yet, but you can ease your symptoms. Your doctor may suggest:
- Steroids, such as prednisone, to lower inflammation
- Inhalers to help you breathe easier
- Oxygen treatment to help you function better
- Medicines to help your cough and open airways
- Meds that calm your immune system to help protect your bronchioles from more damage
If breathing in harmful chemicals is a problem, try to stay away from them. You can also take steps to lower your exposure and help slow down the damage:
- Don't vape; avoid any diacetyl as a flavoring.
- Don't smoke marijuana to lower exposure to acetaldehydes.
- Wear protective gear at work if you're around chemicals, or change jobs if possible.
Popcorn Lung FAQs
How common is popcorn lung?
Popcorn lung rarely happens after an infection, chemical exposure, or from some autoimmune conditions. But your risk is higher if you've had certain types of transplants:
- After a lung transplant, about half the people get popcorn lung within five years.
- After a bone marrow transplant, about 1 in 10 people get popcorn lung within five years.
Will popcorn lung go away?
Popcorn lung doesn't go away on its own because it literally "obliterates" or destroys the tiny airways inside your lungs. But treatments can help you manage your symptoms and sometimes slow the damage.
Does vaping cause popcorn lung?
Vaping is one cause of popcorn lung, also called bronchiolitis obliterans. In fact, vaping works well to deliver chemicals like diacetyl into your lungs. This chemical exposure can lead to inflammation, scarring, and lung problems, including popcorn lung.
How to check if your lungs are healthy?
Keep in mind that you might not notice popcorn lung at first. Let your doctor know if you have early signs and you:
- Get short of breath, especially with activity
- Cough, usually dry, but some mucus might come up
- Wheeze
- Feel unusually tired, without a reason
